Calculating and monitoring a composite stress index

ABSTRACT

In particular embodiments, a method includes accessing data streams from a first group of physiological sensors monitoring a person, a second group of deconfounding sensors monitoring the person, and a third group of sensors monitoring a stressor, analyzing data sets collected from the person when the person is exposed and not exposed to the stressor, and determining a current stress factor for the stressor with respect to the person based on the analysis.

TECHNICAL FIELD

This disclosure generally relates to sensors and sensor networks formonitoring and analyzing a person's health.

BACKGROUND

A sensor network may include distributed autonomous sensors. Uses ofsensor networks include but are not limited to military applications,industrial process monitoring and control, machine health monitoring,environment and habitat monitoring, utility usage, healthcare andmedical applications, home automation, and traffic control. A sensor ina sensor network is typically equipped with a communications interface,a controller, and an energy source (such as a battery).

A sensor typically measures a physical quantity and converts it into asignal that an observer or an instrument can read. For example, amercury-in-glass thermometer converts a measured temperature intoexpansion and contraction of a liquid that can be read on a calibratedglass tube. A thermocouple converts temperature to an output voltagethat a voltmeter can read. For accuracy, sensors are generallycalibrated against known standards.

Detecting and managing stress is a significant problem in modern-daymedicine. If fact, many doctors argue that stress and stress-relatedsymptoms are a major cause of death. Consequently, methods and systemsfor modeling, measuring, and monitoring stress in a person providesignificant health benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example sensor network.

FIG. 2A illustrates an example data flow in a sensor network.

FIG. 2B illustrates an example sensor.

FIG. 3 illustrates an example method for triggering user queries basedon sensor inputs.

FIG. 4 illustrates an example sensor for collecting psychological andbehavioral data from a person.

FIG. 5 illustrates an example method for collecting psychological andbehavioral data from a person.

FIG. 6A illustrates an example data aggregation system and data flow toand from the data aggregation system.

FIG. 6B illustrate an example data aggregation system and data flow toand from the data aggregation system.

FIG. 7A illustrates an example of a data aggregation system.

FIG. 7B illustrates an example of a data aggregation system.

FIG. 8 illustrates an example method for aggregating data streams fromsensors.

FIG. 9 illustrates an example method for creating a stress profile usingrenal Doppler sonography.

FIG. 10 illustrates an example method for monitoring stress using astress profile created by renal Doppler sonography.

FIG. 11 illustrates an example method for monitoring stress usingpsychological or behavioral data.

FIG. 12 illustrates an example method for monitoring stress usingaccelerometer data.

FIG. 13 illustrates an example method for monitoring stress usingenvironmental data.

FIG. 14 illustrates an example method for calculating a stress factorfor a stressor.

FIG. 15 illustrates an example method for calculating a stress factorfor a therapy.

FIG. 16 illustrates an example computer system.

FIG. 17 illustrates an example network environment.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Sensor Networks

FIG. 1 illustrates an example sensor network 100. Sensor network 100comprises a sensor array 110, an analysis system 180, and display system190. Sensor network 100 enables the collecting, processing, analyzing,sharing, visualizing, displaying, archiving, and searching of sensordata. The data collected by sensors 112 in sensor array 110 may beprocessed, analyzed, and stored using the computational and data storageresources of sensor network 100. This may be done with both centralizedand distributed computational and storage resources. Sensor network 100may integrate heterogeneous sensor, data, and computational resourcesdeployed over a wide area. Sensor network 100 may be used to undertake avariety of tasks, such as physiological, psychological, behavioral, andenvironmental monitoring and analysis.

A sensor array 110 comprises one or more sensors 112. A sensor 112receives a stimulus and converts it into a data stream. The sensors 112in sensor array 110 may be of the same type (e.g., multiplethermometers) or various types (e.g., a thermometer, a barometer, and analtimeter). A sensor array 110 may transmit one or more data streamsbased on the one or more stimuli to one or more analysis systems 180over any suitable network. In particular embodiments, a sensor 112'sembedded processors may perform certain computational activities (e.g.,image and signal processing) that could also be performed by othercomponents of sensor network 100, such as, for example, analysis system180 or display system 190.

As used herein, a sensor 112 in a sensor array 110 is described withrespect to a subject. Therefore, a sensor 112 may be personal or remotewith respect to the subject. Personal sensors receive stimuli that arefrom or related to the subject. Personal sensors may include, forexample, sensors that are affixed to or carried by the subject (e.g., aheart-rate monitor, an input by the subject into a smart phone), sensorsthat are proximate to the subject (e.g., a thermometer in the room wherethe subject is located), or sensors that are otherwise related to thesubject (e.g., GPS position of the subject, a medical report by thesubject's doctor, a subject's email inbox). Remote sensors receivestimulus that is external to or not directly related to the subject.Remote sensors may include, for example, environmental sensors (e.g.,weather balloons, stock market ticker), network data feeds (e.g., newsfeeds), or sensors that are otherwise related to external information. Asensor 112 may be both personal and remote depending on thecircumstances. As an example and not by way of limitation, if thesubject is a particular person, a thermometer in a subject's home may beconsidered personal while the subject is at home, but remote when thesubject is away from home. As another example and not by way oflimitation, if the subject is a particular home, a thermometer in thehome may be considered personal to the home regardless of whether aperson is in the home or away.

The sensor array 110 may further comprise one or more data aggregationnodes 114. A node 114 may access one or more data streams from one ormore sensors 112 in the sensor array 110. The node 114 may then monitor,store, and analyze one or more data streams from the sensors 112. Inparticular embodiments, the node 114 may synchronize a plurality of datastreams from a plurality of sensors 112. A node 114 may transmit one ormore data streams based on the one or more data streams received fromthe sensors 112 to one or more analysis systems 180 over any suitablenetwork. In particular embodiments, a node 114's embedded processors mayperform certain computational activities (e.g., image and signalprocessing) that could also be performed by other components of sensornetwork 100, such as, for example, analysis system 180 or display system190. In particular embodiments, a node 114 may analyze one or more datastreams from one or more sensors 112 and generate one or more derivativedata streams that may be synchronized, modified, stored, transmitted,and analyzed.

Analysis system 180 may monitor, store, and analyze one or more datastreams from sensor array 110. Analysis system 180 may havesubcomponents that are local 120, remote 150, or both. Display system190 may render, visualize, display, message, and publish to one or moreusers based on the output of analysis system 180. Display system 190 mayhave subcomponents that are local 130, remote 140, or both.

As used herein, the analysis and display components of sensor network100 are described with respect to a sensor 112. Therefore, a componentmay be local or remote with respect to the sensor 112. Local components(i.e., local analysis system 120, local display system 130) may includecomponents that are built into or proximate to the sensor 112. As anexample and not by way of limitation, a sensor 112 could include anintegrated computing system and LCD monitor that function as localanalysis system 120 and local display system 130. Remote components(i.e., remote analysis system 150, remote display system 190) mayinclude components that are external to or independent of the sensor112. As another example and not by way of limitation, a sensor 112 couldtransmit a data stream over a network to a remote server at a medicalfacility, wherein dedicated computing systems and monitors function asremote analysis system 150 and remote display system 190. In particularembodiments, each sensor 112 in sensor array 110 may utilize eitherlocal or remote display and analysis components, or both. In particularembodiments, a user may selectively access, analyze, and display thedata streams from one or more sensors 112 in sensor array 110. This maybe done, for example, as part of running a specific application or dataanalysis algorithm. The user could access data from specific types ofsensors 112 (e.g., all thermocouple data), from sensors 112 that measurespecific types of data (e.g., all environmental sensors), or based onother criteria.

Although FIG. 1 illustrates a particular arrangement of sensor array110, sensors 112, node 114, analysis system 180, local analysis system120, remote analysis system 150, display system 190, local displaysystem 130, remote display system 140, and network 160, this disclosurecontemplates any suitable arrangement of sensor array 110, sensors 112,node 114, analysis system 180, local analysis system 120, remoteanalysis system 150, display system 190, local display system 130,remote display system 140, and network 160. As an example and not by wayof limitation, two or more of sensor array 110, sensors 112, nodes 114,analysis system 180, local analysis system 120, remote analysis system150, display system 190, local display system 130, and remote displaysystem 140 may be connected to each other directly, bypassing network160. As another example, one or more sensors 112 may be connecteddirectly to communication network 160, without being part of a sensorarray 110. As another example, two or more of sensor array 110, sensors112, node 114, analysis system 180, local analysis system 120, remoteanalysis system 150, display system 190, local display system 130, andremote display system 140 may be physically or logically co-located witheach other in whole or in part. Moreover, although FIG. 1 illustrates aparticular number of sensor arrays 110, sensors 112, nodes 114, analysissystems 180, local analysis systems 120, remote analysis systems 150,display systems 190, local display systems 130, remote display systems140, and networks 160, this disclosure contemplates any suitable numberof sensor arrays 110, sensors 112, nodes 114, analysis systems 180,local analysis systems 120, remote analysis systems 150, display systems190, local display systems 130, remote display systems 140, and networks160. As an example and not by way of limitation, sensor network 100 mayinclude multiple sensor arrays 110, sensors 112, nodes 114, analysissystems 180, local analysis systems 120, remote analysis systems 150,display systems 190, local display systems 130, remote display systems140, and networks 160.

This disclosure contemplates any suitable network 160. As an example andnot by way of limitation, one or more portions of network 160 mayinclude an ad hoc network, an intranet, an extranet, a virtual privatenetwork (VPN), a local area network (LAN), a wireless LAN (WLAN), a widearea network (WAN), a wireless WAN (WWAN), a metropolitan area network(MAN), a portion of the Internet, a portion of the Public SwitchedTelephone Network (PSTN), a cellular telephone network, or a combinationof two or more of these. Network 160 may include one or more networks160. Similarly, this disclosure contemplates any suitable sensor array110. As an example and not by way of limitation, one or more portions ofsensor array 110 may include an ad hoc network, an intranet, anextranet, a VPN, a LAN, a WLAN, a WAN, a WWAN, a MAN, a portion of theInternet, a portion of the PSTN, a cellular telephone network, or acombination of two or more of these. Sensor array 110 may include one ormore sensor arrays 110.

Connections 116 may connect sensor array 110, sensors 112, node 114,analysis system 180, local analysis system 120, remote analysis system150, display system 190, local display system 130, and remote displaysystem 140 to network 160 or to each other. Similarly, connections 116may connect sensors 112 to each other or to node 114 in sensor array 110(or to other equipment in sensor array 110) or to network 160. Thisdisclosure contemplates any suitable connections 116. In particularembodiments, one or more connections 116 include one or more wireline(such as, for example, Digital Subscriber Line (DSL) or Data Over CableService Interface Specification (DOCSIS)), wireless (such as, forexample, Wi-Fi or Worldwide Interoperability for Microwave Access(WiMAX)) or optical (such as, for example, Synchronous Optical Network(SONET) or Synchronous Digital Hierarchy (SDH)) connections. Inparticular embodiments, one or more connections 116 each include an adhoc network, an intranet, an extranet, a VPN, a LAN, a WLAN, a WAN, aWWAN, a MAN, a portion of the Internet, a portion of the PSTN, acellular telephone network, another connection 116, or a combination oftwo or more such connections 116. Connections 116 need not necessarilybe the same throughout sensor network 100. One or more first connections116 may differ in one or more respects from one or more secondconnections 116.

FIG. 2A illustrates an example data flow in a sensor network. In variousembodiments, one or more sensors in a sensor array 210 may receive oneor more stimuli. The sensor array 210 may transmit one or more datastreams based on the one or more stimuli to one or more analysis systems280 over any suitable network. As an example and not by way oflimitation, one sensor could transmit multiple data streams to multipleanalysis systems. As another example and not by way of limitation,multiple sensors could transmit multiple data streams to one analysissystem.

In particular embodiments, the sensors in sensor array 210 each producetheir own data stream, which is transmitted to analysis system 280. Inother embodiments, one or more sensors in sensor array 210 each producetheir own data stream, which is transmitted to a node. In yet otherembodiments, one or more sensors in sensor array 210 have their outputcombined into a single data stream.

Analysis system 280 may monitor, store, and analyze one or more datastreams. Analysis system 280 may be local, remote, or both. Analysissystem 280 may transmit one or more analysis outputs based on the one ormore data streams to one or more display systems 290. As an example andnot by way of limitation, one analysis system could transmit multipleanalysis outputs to multiple display systems. As another example and notby way of limitation, multiple analysis systems could transmit multipleanalysis outputs to one display system. Analysis system 280 may alsostore one or more analysis outputs for later processing.

A display system 290 may render, visualize, display, message, andpublish to one or more users based on the one or more analysis outputs.A display system 290 may be local, remote, or both. In variousembodiments, a sensor array 210 may transmit one or more data streamsdirectly to a display system 290. This may allow, for example, displayof stimulus readings by the sensor.

Although FIG. 2A illustrates a particular arrangement of sensor array210, analysis system 280, and display system 290, this disclosurecontemplates any suitable arrangement of sensor array 210, analysissystem 280, and display system 290. Moreover, although FIG. 2Aillustrates a particular data flow between sensor array 210, analysissystem 280, and display system 290, this disclosure contemplates anysuitable data flow between sensor array 210, analysis system 280, anddisplay system 290.

Sensors

FIG. 2B illustrates an example sensor 212 and data flow to and from thesensor. A sensor 212 is a device which receives and responds to astimulus. Here, the term “stimulus” means any signal, property,measurement, or quantity that may be detected and measured by a sensor212.

In particular embodiments, a sensor 212 receives stimuli from a subject.As an example and not by way of limitation, a subject may be a person(or group of persons or entity), place (such as, for example, ageographical location), or thing (such as, for example, a building,road, or car). Although this disclosure describes particular types ofsubjects, this disclosure contemplates any suitable types of subjects.In particular embodiments, one or more subjects of one or more sensors112 may be a user of other components of sensor network 100, such asother sensors 112, analysis system 180, or display system 190. As such,the terms “subject” and “user” may refer to the same person, unlesscontext suggests otherwise.

A sensor 212 responds to a stimulus by generating a data streamcorresponding to the stimulus. A data stream may be a digital or analogsignal that can be transmitted over any suitable transmission medium andfurther used in electronic devices. As used herein, the term “sensor” isused broadly to describe any device that receives a stimulus andconverts it into a data stream. The present disclosure assumes that thedata stream output from a sensor 212 is transmitted to an analysissystem, unless otherwise specified.

In particular embodiments, one or more sensors 212 each include astimulus receiving element (i.e., sensing element), a communicationelement, and any associate circuitry. Sensors 212 generally are small,battery powered, portable, and equipped with a microprocessor, internalmemory for data storage, and a transducer or other component forreceiving stimulus. However, a sensor 212 may also be an assay, test, ormeasurement. A sensor 212 may interface with a personal computer andutilize software to activate the sensor 212 and to view and analyze thecollected data. A sensor 212 may also have a local interface device(e.g., keypad, LCD) allowing it to be used as a stand-alone device. Inparticular embodiments, a sensor 212 may include one or morecommunication elements that may receive or transmit information (such asdata streams) over a communication channel, for example to one or moreother components in a sensor network.

In particular embodiments, one or more sensors 212 may measure a varietyof things, including physiological, psychological, behavioral, andenvironmental stimulus. Physiological stimulus may include, for example,physical aspects of a person (e.g., stretch, motion of the person, andposition of appendages); metabolic aspects of a person (e.g., glucoselevel, oxygen level, osmolality), biochemical aspects of a person (e.g.,enzymes, hormones, neurotransmitters, cytokines), and other aspects of aperson related to physical health, disease, and homeostasis.Psychological stimulus may include, for example, emotion, mood, feeling,anxiety, stress, depression, and other psychological or mental states ofa person. Behavioral stimulus may include, for example, behavior relateda person (e.g., working, socializing, arguing, drinking, resting,driving), behavior related to a group (e.g., marches, protests, mobbehavior), and other aspects related to behavior. Environmental stimulusmay include, for example, physical aspects of the environment (e.g.,light, motion, temperature, magnetic fields, gravity, humidity,vibration, pressure, electrical fields, sound, GPS location),environmental molecules (e.g., toxins, nutrients, pheromones),environmental conditions (e.g., pollen count, weather), other externalcondition (e.g., traffic conditions, stock market information, newsfeeds), and other aspects of the environment.

As an example and not by way of limitation, particular embodiments mayinclude one or more of the following types of sensors: Accelerometer;Affinity electrophoresis; Air flow meter; Air speed indicator; Alarmsensor; Altimeter; Ammeter; Anemometer; Arterial blood gas sensor;Attitude indicator; Barograph; Barometer; Biosensor; Bolometer; Boostgauge; Bourdon gauge; Breathalyzer; Calorie Intake Monitor; calorimeter;Capacitive displacement sensor; Capillary electrophoresis; Carbondioxide sensor; Carbon monoxide detector; Catalytic bead sensor;Charge-coupled device; Chemical field-effect transistor; Chromatograph;Colorimeter; Compass; Contact image sensor; Current sensor; Depth gauge;DNA microarray; Electrocardiograph (ECG or EKG); Electrochemical gassensor; Electrolyte-insulator-semiconductor sensor; Electromyograph(EMG); Electronic nose; Electro-optical sensor; Exhaust gas temperaturegauge; Fiber optic sensors; Flame detector; Flow sensor; Fluxgatecompass; Foot switches; Force sensor; Free fall sensor; Galvanic skinresponse sensor; Galvanometer; Gardon gauge; Gas detector; Gas meter;Geiger counter; Geophone; Goniometers; Gravimeter; Gyroscope; Halleffect sensor; Hall probe; Heart-rate sensor; Heat flux sensor;High-performance liquid chromatograph (HPLC); Hot filament ionizationgauge; Hydrogen sensor; Hydrogen sulfide sensor; Hydrophone;Immunoassay, Inclinometer; Inertial reference unit; Infrared pointsensor; Infra-red sensor; Infrared thermometer; Insulin monitors;Ionization gauge; Ion-selective electrode; Keyboard; Kinestheticsensors; Laser rangefinder; Leaf electroscope; LED light sensor; Linearencoder; Linear variable differential transformer (LVDT); Liquidcapacitive inclinometers; Magnetic anomaly detector; Magnetic compass;Magnetometer; Mass flow sensor; McLeod gauge; Metal detector; MHDsensor; Microbolometer; Microphone; Microwave chemistry sensor;Microwave radiometer; Mood sensor; Motion detector; Mouse; Multimeter;Net radiometer; Neutron detection; Nichols radiometer; Nitrogen oxidesensor; Nondispersive infrared sensor; Occupancy sensor; Odometer;Ohmmeter; Olfactometer; Optode; Oscillating U-tube; Oxygen sensor; Painsensor; Particle detector; Passive infrared sensor; Pedometer;Pellistor; pH glass electrode; Photoplethysmograph; Photodetector;Photodiode; Photoelectric sensor; Photoionization detector;Photomultiplier; Photoresistor; Photoswitch; Phototransistor; Phototube;Piezoelectric accelerometer; Pirani gauge; Position sensor;Potentiometric sensor; Pressure gauge; Pressure sensor; Proximitysensor; Psychrometer; Pulse oximetry sensor; Pulse wave velocitymonitor; Radio direction finder; Rain gauge; Rain sensor; Redoxelectrode; Reed switch; Resistance temperature detector; Resistancethermometer; Respiration sensor; Ring laser gyroscope; Rotary encoder;Rotary variable differential transformer; Scintillometer; Seismometer;Selsyn; Shack-Hartmann; Silicon bandgap temperature sensor; Smokedetector; Snow gauge; Soil moisture sensor; Speech monitor; Speedsensor; Stream gauge; Stud finder; Sudden Motion Sensor; Tachometer;Tactile sensor; Temperature gauge; Thermistor; Thermocouple;Thermometer; Tide gauge; Tilt sensor; Time pressure gauge; Touch switch;Triangulation sensor; Turn coordinator; Ultrasonic thickness gauge;Variometer; Vibrating structure gyroscope; Voltmeter; Water meter;Watt-hour meter; Wavefront sensor; Wired glove.; Yaw rate sensor; andZinc oxide nanorod sensor. Although this disclosure describes particulartypes of sensors, this disclosure contemplates any suitable types ofsensors.

A biosensor is a type of sensor 112 that receives a biological stimulusand converts it into a data stream. As used herein, the term “biosensor”is used broadly.

In particular embodiments, a biosensor may be a device for the detectionof an analyte. An analyte is a substance or chemical constituent that isdetermined in an analytical procedure. For instance, in an immunoassay,the analyte may be the ligand or the binder, while in blood glucosetesting, the analyte is glucose. In medicine, analyte typically refersto the type of test being run on a patient, as the test is usuallydetermining the existence and/or concentration of a chemical substancein the human body.

A common example of a commercial biosensor is a blood glucose monitor,which uses the enzyme glucose oxidase to break blood glucose down. Indoing so, it first oxidizes glucose and uses two electrons to reduce theFAD (flavin adenine dinucleotide, a component of the enzyme) to FADH₂(1,5-dihydro-FAD). This in turn is oxidized by the electrode (acceptingtwo electrons from the electrode) in a number of steps. The resultingcurrent is a measure of the concentration of glucose. In this case, theelectrode is the transducer and the enzyme is the biologically activecomponent.

In particular embodiments, a biosensor combines a biological componentwith a physicochemical detector component. A typical biosensorcomprises: a sensitive biological element (e.g., biological material(tissue, microorganisms, organelles, cell receptors, enzymes,antibodies, nucleic acids, etc.), biologically derived material,biomimic); a physicochemical transducer/detector element (e.g. optical,piezoelectric, electrochemical) that transforms the signal (i.e. inputstimulus) resulting from the interaction of the analyte with thebiological element into another signal (i.e. transducers) that may bemeasured and quantified; and associated electronics or signal processorsgenerating and transmitting a data stream corresponding to the inputstimulus. The encapsulation of the biological component in a biosensormay be done by means of a semi-permeable barrier (e.g., a dialysismembrane or hydrogel), a 3D polymer matrix (e.g., by physically orchemically constraining the sensing macromolecule), or by other means.

Sensor Sampling Rates

In particular embodiments, a sensor 112 may sample input stimulus atdiscrete times. The sampling rate, sample rate, or sampling frequencydefines the number of samples per second (or per other unit) taken froma continuous or semi-continuous stimulus to make a discrete data signal.For time-domain signals, the unit for sampling rate may be 1/s (Hertz).The inverse of the sampling frequency is the sampling period or samplinginterval, which is the time between samples. The sampling rate of asensor 112 may be controlled locally, remotely, or both.

In particular embodiments, one or more sensors 112 in the sensor array110 may have a dynamic sampling rate. Dynamic sampling is performed whena decision to change the sampling rate is taken if the current outcomeof a process is within or different from some specified value or rangeof values. As an example and not by way of limitation, if the stimulusis different from the outcome predicted by some model or falls outsidesome threshold range, the sensor 112 may increase or decrease itssampling rate in response. Dynamic sampling may be used to optimize theoperation of the sensors 112 or influence the operation of actuators tochange the environment.

In particular embodiments, the sampling rate of a sensor 112 may bebased on receipt of a particular stimulus. As an example and not by wayof limitation, an accelerometer may have a default sample rate of 1/s,but may increase its sampling rate to 60/s whenever it measures anon-zero value, and then may return to a 1/s sampling rate after getting60 consecutive samples equal to zero. As another example and not by wayof limitation, if the stimulus measured over a particular range of timedoes vary significantly, the sensor 112 may reduce its sampling rate.

In particular embodiments, the sampling rate of a sensor 112 may bebased on input from one or more components of sensor network 100. As anexample and not by way of limitation, a heart rate monitor may have adefault sampling rate of 1/min, but may increase the its sampling ratein response to a signal or instruction from analysis system 180.

In particular embodiments, one or more sensors 112 in the sensor array110 may increase or decrease the precision at which the sensors 112sample input. As an example and not by way of limitation, a glucosemonitor may use four bits to record a user's blood glucose level bydefault. However, if the user's blood glucose level begins varyingquickly, the glucose monitor may increase its precision to eight-bitmeasurements.

User-Input Sensors

In particular embodiments, a user-input device may be a sensor 112 insensor array 110. These “user-input sensors” are sensors 112 where thestimulus received by the sensor 112 may be input from a user. The usermay input any suitable information into the sensor 112, includingphysiological, psychological, behavioral, or environmental information.The user may input information about the user (e.g., a user may recordhis psychological state) or about one or more 3rd parties (e.g., adoctor may record information about a patient). A user may provide inputin a variety of ways. User-input may include, for example, inputting aquantity or value into the sensor 112, speaking or providing other audioinput to the sensor 112, and touching or providing other stimulus to thesensor 112. Any client system with a suitable I/O device may serve as auser-input sensor. Suitable I/O devices include alphanumeric keyboards,numeric keypads, touch pads, touch screens, input keys, buttons,switches, microphones, pointing devices, navigation buttons, stylus,scroll dial, another suitable I/O device, or a combination of two ormore of these.

In particular embodiments, an electronic calendar functions as auser-input sensor for gathering behavioral data. A user may input thetime and day for various activities, including appointments, socialinteractions, phone calls, meetings, work, tasks, chores, etc. Eachinputted activity may be further tagged with details, labels, andcategories (e.g., “important,” “personal,” “birthday”). The electroniccalendar may be any suitable personal information manager, such asMicrosoft Outlook, Lotus Notes, Google Calendar, etc. The electroniccalendar may then transmit the activity data as a data stream toanalysis system 180, which could map the activity data over time andcorrelate it with data from other sensors in sensor array 110. Forexample, analysis system 180 may map a heart-rate data stream againstthe activity data stream from an electronic calendar, showing that theuser's heart-rate peaked during a particularly stressful activity (e.g.,dinner with the in-laws).

User Queries and Triggering User Queries Based on Sensor Inputs

In particular embodiments, a sensor 112 may query a user to inputinformation (i.e., stimulus) into the sensor 112. The sensor 112 mayquery the user in any suitable manner, such as, for example, byprompting the user to input information into a suitable I/O device. Thesensor 112 may query the user at any suitable rate or frequency. As anexample and not by way of limitation, a sensor 112 may query a user at astatic interval (e.g., every hour). As another example and not by way oflimitation, a sensor 112 may query a user at a dynamic rate. The dynamicrate may be based on a variety of factors, including prior input intothe sensor 112, data streams from other sensors 112 or nodes 114 insensor array 110, output from analysis system 180, or other suitablefactors. For example, if a heart-rate monitor in sensor array 110indicates an increase in the user's heart-rate, a user-input sensor mayimmediately query the user to input his current activity. Although thisdisclosure describes particular components performing particularprocesses to query a user to input information into a sensor 112, thisdisclosure contemplates any suitable components performing any suitableprocesses to query a user to input information into a sensor 112.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more sensors 112. The sensors may bephysiological, psychological, behavioral, or environmental sensors.Similarly, each data stream may comprise physiological, psychological,behavioral, or environmental data of a person. In particularembodiments, analysis system 180 may access one or more physiologicalsensors, the physiological sensors comprising one or more of aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, anaccelerometer, an electrocardiograph, a glucocorticoid meter, anelectromyograph, another suitable physiological sensor, or two or moresuch sensors. As an example and not by way of limitation, analysissystem 180 may access a data stream from a heart-rate monitor, whereinthe data stream comprises heart-rate data of a person. In particularembodiments, analysis system 180 may access one or more environmentalsensors that are data feeds, the data feeds comprising one or more of astock-market ticker, a weather report, a news feed, a traffic-conditionupdate, a public-health notice, an electronic calendar, a social networknews feed, another suitable data feed, or two or more such data feeds.As an example and not by way of limitation, analysis system 180 mayaccess a stock-market ticker from a data feed, wherein the stock-marketticker comprises stock information. Although this disclosure describesparticular components accessing particular data streams from particularsensors 112, this disclosure contemplates any suitable componentsaccessing any suitable data streams from any suitable sensors 112.

In particular embodiments, analysis system 180 may analyze a data streamin reference to its corresponding set of control parameters. Each sensor112 or data stream may have a corresponding set of control parameters.The set of control parameters consists of data parameters that specifywhen a sensor 112 or data stream is at a normal or expected state. Theset of control parameters may include one or more of a set point for thesensor 112, an operating range for the sensor 112, an operatingthreshold for the sensor 112, a sampling rate for the sensor 112, asample size for the sensor 112, another suitable parameter, or two ormore such parameters. As an example and not by way of limitation, aheart-rate monitor may have a corresponding set of control parametersthat specify that a heart-rate of 60-100 beats/minute is a normal state.As another example and not by way of limitation, a mood sensor 400 mayhave a corresponding set of control parameters that specify that aself-reported psychological state of “stressed” with an intensity of 2or less on a 0-to-4 Likert scale is a normal state. In particularembodiments, analysis system 180 may analyze a plurality of data streamsin references to a plurality of corresponding sets of controlparameters. The set of control parameters may specify when a firstsensor 112 or first data stream is at a normal or expected state basedon data from one or more second sensors 112 or second data streams. Asan example and not by way of limitation, a heart-rate monitor and anaccelerometer may have a corresponding set of control parameters thatspecify that once a period of extended activity has ended, a change inheart-rate of 12 beats/minute² or higher is a normal state (ancontinuously elevated heart rate after exercise may indicate anincreased risk of heart attack). As another example and not by way oflimitation, a mood sensor 400 and a weather report data feed may have acorresponding set of control parameters that specify that when theweather is overcast, a self-reported psychological state of “depressed”with an intensity of 3 or less on a 0-to-4 Likert scale is a normalstate (a person is more likely to be depressed when the weather ispoor). Although this disclosure describes particular componentsanalyzing particular data streams in reference to particular sets ofcontrol parameters, this disclosure contemplates any suitable componentsanalyzing any suitable data streams in reference to any suitable sets ofcontrol parameters.

In particular embodiments, analysis system 180 may analyze a data streamin reference to its corresponding set of control parameters to determineif the data stream deviates from its corresponding set of controlparameters. Analysis system 180 may use any suitable process,calculation, or technique to determine if a data stream deviates fromits corresponding set of control parameters. A sensor 112 or data streamdeviates from its corresponding set of control parameters when one ormore samples in the data stream indicate that the sensor or data streamis not at a normal or expected state. As an example and not by way oflimitation, if a heart-rate monitor has a corresponding set of controlparameters that specify that a heart-rate of 60-100 beats/minute is anormal state, analysis system 180 may compare one or more samples fromthe data stream from the heart-rate monitor with the set of controlparameters corresponding to the heart-rate monitor to identify whetherany of the samples indicate a heart-rate outside of the 60-100beats/minute range. Although this disclosure describes particularcomponents performing particular process to determine if a data streamdeviates from its corresponding set of control parameters, thisdisclosure contemplates any suitable components performing any suitableprocesses to determine if a data stream deviates from its correspondingset of control parameters.

In particular embodiments, analysis system 180 may transmit a query toone or more sensors 112 for physiological, psychological, behavioral, orenvironmental information. The query may ask the user to inputinformation about the user (e.g., asking the user to input hispsychological state) or about one or more 3rd parties (e.g., asking adoctor to input physiological information about a patient). The querymay ask an environment sensor for environment information (e.g., askinga weather sensor for the temperature at the user's location; asking astock ticker for information on the user's stock portfolio). The sensor112 may prompt the user to input data into the sensor 112 in anysuitable manner, such as, for example, by inputting a quantity or valueinto the sensor 112, speaking or providing other audio input to thesensor 112, and touching or providing other stimulus to the sensor 112.The sensor 112 may also automatically sample data without any userinput. In particular embodiments, analysis system 180 may transmit aquery to one or more mood sensors 400 for psychological or behavioraldata of the user. The mood sensor 400 may prompt the user to inputpsychological or behavioral data into mood collection interface 420. Asan example and not by way of limitation, analysis system 180 maytransmit a query to a mood sensor 400 for mood, mood intensity, andactivity data of a user. The mood sensor 400 may display a message orother notification in mood collection interface 420 instructing the userto input mood and activity data into the mood collection interface 420.Although this disclosure describes particular components transmittingparticular queries, this disclosure contemplates any suitable componentstransmitting any suitable queries. Moreover, although this disclosuredescribes transmitting queries to particular sensors 112 for particularinformation, this disclosure contemplates transmitting queries to anysuitable sensors 112 for any suitable information.

In particular embodiments, analysis system 180 may receive one or moredata streams from one or more sensors 112 in response to a query. Thedata streams may contain physiological, psychological, behavioral, orenvironmental data from a sensor 112 in response to the query. Inparticular embodiments, analysis system 180 may receive one or more datastreams from one or more mood sensor 400 in response to a query. Thedata streams from mood sensor 400 may contain psychological orbehavioral data in response to the query. As an example and not by wayof limitation, analysis system 180 may transmit a query to mood sensor400 for mood and mood intensity data of the user. The user may inputthat he is “stressed” with an intensity of 2 on a 0-to-4 Likert scale.The mood sensor 400 may then transmit a data stream comprising theuser's mood and mood intensity data to analysis system 180 in responseto the query, the data stream being received by analysis system 180. Asanother example and not by way of limitation, analysis system 180 maytransmit a query to mood sensor 400 for activity data of the user. Theuser may input that he is “driving.” The mood sensor 400 may thentransmit a data stream comprising the user's activity data to analysissystem 180 in response to the query, the data system being received byanalysis system 180. Although this disclosure describes particularcomponents receiving particular data streams, this disclosurecontemplates any suitable components receiving any suitable datastreams. Moreover, although this disclosure describes receivingparticular data streams in response to particular queries, thisdisclosure contemplates receiving any suitable data streams in responseto any suitable queries.

In particular embodiments, a sensor 112 may query a user to take asample with the sensor 112. The sensor 112 may query the user in anysuitable manner, such as, for example, by prompting the user to use oractivate the sensor 112. As an example and not by way of limitation,analysis system 180 may transmit a query to a blood-glucose monitor forblood-glucose data of a user. The blood-glucose monitor may notify theuser of the query with a suitable audio or visual prompt. The user maythen take a blood sample with the blood-glucose monitor, and theblood-glucose monitor may transmit a data stream based on this sample toanalysis system 180. Although this disclosure describes particularcomponents performing particular processes to query a user to take asample with a sensor 112, this disclosure contemplates any suitablecomponents performing any suitable processes to take a sample with asensor 112.

FIG. 3 illustrates an example method 300 for triggering user queriesbased on sensor inputs. The method begins at step 310, where analysissystem 180 accesses one or more physiological data streams from one ormore physiological sensors, such as sensors 112. The physiological datastreams comprise physiological data of a person. At step 320, analysissystem 180 analyzes each physiological data stream in reference to acorresponding set of control parameters. At step 330, analysis system180 determines if at least one of the physiological data streamsdeviates from its corresponding set of control parameters. If at leastone of the physiological data streams deviates from its correspondingset of control parameters, then analysis system 180 transmits a query toone or more of a mood sensor or a behavioral sensor for mood data of theperson or behavioral data of the person, respectively, at step 340. Butif the physiological data stream do not deviate from their correspondingset of control parameters, then analysis system 180 may return to step310. Although this disclosure describes and illustrates particular stepsof the method of FIG. 3 as occurring in a particular order, thisdisclosure contemplates any suitable steps of the method of FIG. 3occurring in any suitable order. Moreover, although this disclosuredescribes and illustrates particular components carrying out particularsteps of the method of FIG. 3, this disclosure contemplates any suitablecombination of any suitable components carrying out any suitable stepsof the method of FIG. 3.

Mood/Behavioral Sensors

FIG. 4 illustrates an example sensor 400 for collecting psychologicaland behavioral information from a person. This “mood sensor” 400 is atype of user-input sensor that may receive psychological and behavioralinput (i.e., stimulus) from a user. In some embodiments, a user mayinput psychological (i.e., mood) or behavioral (i.e., activity)information about the user. In other embodiments, the user may inputpsychological or behavioral information about one or more 3rd parties(e.g., a doctor may record information about a patient). This disclosureassumes that a user is recording information about the user, unlesscontext suggests otherwise. Mood sensor 400 may server as a mood sensorfor receiving psychological stimulus or as a behavioral sensor forreceiving behavioral stimulus. Although this disclosure describesparticular components performing particular processes to collectpsychological and behavioral information from a person, this disclosurecontemplates any suitable components performing any suitable processesto collect psychological and behavioral information from a person.Moreover, although this disclosure describes mood sensor 400 collectingparticular types of psychological and behavior information about aperson, this disclosure contemplates mood sensor 400 collecting anysuitable types of psychological or behavioral information.

In particular embodiments, mood sensor 400 includes a softwareapplication that may be executed on client system 410. FIG. 4illustrates a smart phone as an example client system 410, however anysuitable user-input device may be used (e.g., cellular phone, personaldigital assistant, personal computer, tablet computer, wearablecomputer, etc.). In some embodiments, a user may execute an applicationon client system 410 to access mood collection interface 420. In otherembodiments, a user may use a browser client or other application onclient system 410 to access mood collection interface 420 over a mobilenetwork (or other suitable network). Mood collection interface 420 maybe configured to receive signals from the user. As an example and not byway of limitation, the user may click, touch, speak, gesture, orotherwise interact with mood collection interface 420 to select andinput psychological or behavioral information, or to perform otheractions.

In particular embodiments, mood sensor 400 may include one or more of amood input widget 430, a mood intensity input widget 440, an activityinput widget 450, or a clock 460. Mood input widget 430 may be athree-by-three grid of mood icons, wherein each icon has a uniquesemantic label and color. The grid illustrated in FIG. 3 shows thefollowing example moods and colors:

Mood/Psychological State Color Stressed Yellow Alert Orange Excited PinkAngry Red Unsure Grey Happy Green Depressed Maya blue Quiet MauveRelaxed Light cornflower blue

The user may touch one or more of the mood icons to input his currentmood (i.e., psychological state). Mood intensity widget 440 is a rowwith numbered icons ranging from one to four that each correspond to alevel of intensity of a psychological state. The numbers range from thelowest to highest intensity, with one being the lowest and four beingthe highest. The user may touch one of the numbers to input an intensitycorresponding to a selected mood. In particular embodiments, the moodintensity corresponds to a standard psychometric scale (e.g., Likertscale). Activity input widget 450 is a drop-down menu containing a listof activities (i.e., behavioral states). The list is not illustrated,but could include a variety of behavioral states, such as sleeping,eating, working, driving, arguing, etc. The user may touch the drop-downmenu to input one or more behavioral states. In particular embodiments,the selected behavioral state may correspond to a selected psychologicalstate. Clock 460 provides the current time according to client system410. This time may be automatically inputted as a timestamp to any otherinputs on mood collection interface 420. In particular embodiments, atime or duration of the psychological or behavioral state may beinputted manually by the user. Although this disclosure describes andFIG. 4 illustrates mood sensor 400 having particular components, thisdisclosure contemplates mood sensor 400 having any suitable components.Moreover, although this disclosure describes and FIG. 4 illustrates moodsensor 400 collecting psychological and behavioral information usingparticular components, this disclosure contemplates mood sensor 400collecting psychological or behavioral information using any suitablecomponents. As an example and not by way of limitation, psychological orbehavioral information about a user may be entered manually by the userwithout the use of widgets, icons, drop-down menus, or timestamps. Thiswould allow the user to input a variety of psychological or behavioralinformation for any time or time period.

In particular embodiments, mood sensor 400 may be a sensor 112 in sensorarray 110. After receiving the psychological or behavioral data, themood sensor 400 may transmit the data as one or more data streams tonode 114, analysis system 180, or another suitable system.

In particular embodiments, mood sensor 400 may query a user to inputpsychological or behavioral information. The user may input any suitablepsychological or behavioral information into the mood sensor 400. Theuser may input information about the user (e.g., a user may record hispsychological state) or about one or more 3rd parties (e.g., apsychiatrist may record psychological information about a patient). Themood sensor 400 may query the user at any suitable rate or frequency. Asan example and not by way of limitation, mood sensor 400 may query auser at a static interval (e.g., every hour). As another example and notby way of limitation, mood sensor 400 may query a user at a dynamicrate. The dynamic rate may be based on a variety of factors, includingprior input into mood sensor 400, data streams from other sensors 112 ornodes 114 in sensor array 110, output from analysis system 180, requestsor queries from other systems, or other suitable factors. For example,if the user inputs that he is “angry” with an intensity of “4,” moodsensor 400 may begin querying the user every 15 minutes until the userindicates the intensity of his mood has dropped to “2” or less. Inanother example, if a heart-rate monitor in sensor array 110 indicatesan increase in the user's heart-rate, mood sensor 400 may query the userto input his current psychological and behavioral state. In yet anotherexample, if the user's electronic calendar indicates that he has anappointment tagged as “important,” mood sensor 400 may query the user toinput his psychological state immediately before and after theappointment. Although this disclosure describes particular componentsperforming particular processes to query a user to input psychologicalor behavioral information into mood sensor 400, this disclosurecontemplates any suitable components performing any suitable processesto query a user to input psychological or behavioral information intomood sensor 400.

In particular embodiments, mood sensor 400 may administer one or moretherapies or therapeutic feedbacks. A therapy may be provided based on avariety of factors. Mood sensor 400 may provide therapeutic feedback tothe user either during or after the user inputs a negative psychologicalor behavioral state. As an example and not by way of limitation, if theuser touches the “angry” button, the display may change to show acalming image of puppies playing in the grass. Mood sensor 400 may alsoprovide therapeutic feedback to the user based on output from analysissystem 180. As an example and not by way of limitation, if a heart-ratemonitor in sensor array 110 indicates an increase in the user'sheart-rate, and the user inputs “stressed” into mood sensor 400, theanalysis system 180 may determine that a therapeutic feedback is needed.In response to this determination, mood sensor 400 may play relaxingmusic to calm the user. Mood sensor 400 may deliver a variety oftherapies, such as interventions, biofeedback, breathing exercises,progressive muscle relaxation exercises, presentation of personal media(e.g., music, personal pictures, etc.), offering an exit strategy (e.g.,calling the user so he has an excuse to leave a stressful situation),references to a range of psychotherapeutic techniques, and graphicalrepresentations of trends (e.g., illustrations of health metrics overtime), cognitive reframing therapy, and other therapeutic feedbacks.Mood sensor 400 may also provide information on where the user can seekother therapies, such as specific recommendations for medical careproviders, hospitals, etc. Although this disclosure describesadministering particular therapeutic feedbacks, this disclosurecontemplates administering any suitable therapeutic feedbacks. Moreover,although this disclosure describes administering therapeutic feedbacksin a particular manner, this disclosure contemplates administeringtherapeutic feedbacks in any suitable manner.

In particular embodiments, mood sensor 400 may be used to access anddisplay psychological or behavioral data related to the user on displaysystem 190. Display system 190 may display data on mood collectioninterface 420 (i.e., the smartphone's touch screen) or another suitabledisplay. Mood sensor 400 may access a local data store (e.g., priorpsychological and behavioral input stored on the user's smart phone) ora remote data store (e.g., medical records from the user's hospital)over any suitable network. Mood sensor 400 may access and display moodand activity information previously recorded by mood sensor 400. As anexample and not by way of limitation, the user could click on the“happy” button to access data showing the intensity, behavior, and timeassociated with each input of “happy” by the user on mood sensor 400.Mood sensor 400 may also access and display data recorded by othersensors 112 or medical procedures. As an example and not by way oflimitation, the user could click on the “depressed” button to accessdata from one or more other sensors 112 in sensor array 110 (e.g.,heart-rate sensor data, pulse oximetry sensor data, etc.) thatcorrespond to each input of “depressed” by the user on mood sensor 400.Although this disclosure describes accessing and displaying particularpsychological and behavioral data, this disclosure contemplatesaccessing and displaying any suitable psychological or behavioral data.

FIG. 5 illustrates an example method 500 for collecting psychologicaland behavioral information from a person. A user of mood sensor 400 mayfirst access mood collection interface 420 on client system 410 at step510. The user may select one or more moods (i.e., psychological states)on mood input widget 430 by touching one of the mood icons at step 520.The user may select an intensity level of the selected mood on moodintensity input widget 440 at step 530. The user may select an activity(i.e., behavioral state) coinciding with the selected mood on activityinput widget 450 at step 540. After all three inputs are entered by theuser, mood sensor 400 may automatically record the inputs or the usermay indicate that he is done inputting moods and activities by clicking“ok” or providing some other input at step 550. At this step, the moodsensor may also record a time indication coinciding with the inputs.Finally, mood sensor 400 may transmit a data stream based on one or moreof the mood, intensity, activity, or time inputs to analysis system 180at step 560. Although this disclosure describes and illustratesparticular steps of the method of FIG. 5 as occurring in a particularorder, this disclosure contemplates any suitable steps of the method ofFIG. 5 occurring in any suitable order. Moreover, although thisdisclosure describes and illustrates particular components carrying outparticular steps of the method of FIG. 5, this disclosure contemplatesany suitable combination of any suitable components carrying out anysuitable steps of the method of FIG. 5.

Data Feeds as Sensors

In particular embodiments, a sensor 112 may be a data feed. A data feedmay be a computing system that receives and aggregates physiological,psychological, behavioral, or environmental data from one or moresources and transmits one or more data streams based on the aggregateddata. Alternatively, a data feed may be the one or more data streamsbased on the aggregated data. As an example and not by way oflimitation, data feeds may be stock-market tickers, weather reports,news feeds, traffic-condition updates, public-health notices, electroniccalendars, data from one or more other users (such as, for example,physiological, psychological, or behavioral data from another user), orany other suitable data feeds. A data feed may contain both personal andremote data, as discussed previously. A data feed may be from anysuitable computing device (such as, for example, computer system 1600).

The example data feeds illustrated and described herein are provided forillustration purposes only and are not meant to be limiting. Thisdisclosure contemplates the use of any suitable data feed.

Data Streams

In particular embodiments, a data stream comprises one or more datatransmitted from one or more sensors 112 or from one or more nodes 114in sensor array 110. A data stream may be a digital or analog signalthat may be transmitted over any suitable transmission medium andfurther used in electronic devices. Sensor array 110 may transmit one ormore data streams based on one or more stimuli to one or more analysissystems 180 over any suitable network.

A data stream may include signals from a variety of types of sensors112, including physiological, psychological, behavioral, andenvironmental sensors. A sensor 112 generates a data streamcorresponding to the stimulus it receives. As an example and not by wayof limitation, a physiological sensor (e.g., an accelerometer) generatesa physiological data stream (e.g., an accelerometer data stream, whichincludes, for example, data on the acceleration of a subject over time).

Sensor data may include any suitable information. In particularembodiments, sensor data includes measurements taken by one or moresensors 112. Sensor data may include samples that may have any suitableformat. In particular embodiments, the format of the samples may be atuple (or ordered set) that has one or more data parameters, and aparticular sample may be a tuple of one or more values for the one ormore data parameters. As an example and not by way of limitation, atuple format (t, p) may have data parameters time t and pressure p, anda particular sample (t0, p0) may have values pressure p0 measured attime t0. The tuple format may include any suitable data parameters, suchas one or more sensor parameters and/or one or more test parameters. Asensor parameter may correspond to one or more sensors 112, and a sensorvalue may record one or more measurements taken by one or more sensors112. As an example and not by way of limitation, a sensor value mayrecord a measurement taken by a sensor 112. A test parameter maycorrespond to a factor that describes a temporal, spatial, and/orenvironmental feature of a measurement process, and a test value mayrecord the value of the feature when the measurements are taken. As anexample and not by way of limitation, the parameter may be time and theparameter value may record a particular time at which measurements aretaken.

In particular embodiments, a sensor 112 may transmit one or more data atdiscrete times. The transmitting rate, transmission rate, ortransmitting frequency defines the number of transmissions per second(or per other unit) sent by a sensor to make a discrete data signal. Fortime-domain signals, the unit for transmitting rate may be 1/s (Hertz).The inverse of the transmitting frequency is the transmitting period ortransmitting interval, which is the time between transmissions. Thedatum may be transmitted continuously, periodically, randomly, or withany other suitable frequency or period. This may or may not correlatewith the sampling rate of the sensor.

Reference to sensor data may encompass a sensor data stream, and viceversa, where appropriate. Sensor data may relate to a sensor subject,wherein the sensor 112 receives stimulus from or related to the subject.Sensor data or a data stream may relate to a sensor subject in anysuitable way. As an example and not by way of limitation, sensor datamay relate to a sensor subject because one or more sensors 112 generatedthe sensor data from one or more stimuli produced by the sensor subject.As another example and not by way of limitation, sensor data may relateto a sensor subject because the sensor data may provide insight orfurther understanding of the sensor subject. As yet another example andnot by way of limitation, sensor data may relate to a sensor subjectbecause it may help detect or predict the occurrence of one or moreproblems or events concerning the sensor subject. As yet another exampleand not by way of limitation, sensor data may relate to a sensor subjectbecause it may facilitate monitoring of the sensor subject.

Data Acquisition

In particular embodiments, the components of sensor network 100 mayutilize some type of data acquisition system to further process the datastream signal for use by analysis system 180. As an example and not byway of limitation, a data acquisition system may convert an analogwaveforms signal into a digital value. As another example and not by wayof limitation, the data acquisition system may convert decimal valuesinto binary values. The data acquisition system may be local, forexample, integrated into a sensor 112 in sensor array 110 or into localanalysis system 120. The data acquisition system may also be remote, forexample, integrated into remote analysis system 150 or an independentsystem.

In particular embodiments, the data acquisition system may perform oneor more signal conditioning processes (for example, if a signal from asensor 112 is not suitable for the type of analysis system 180 beingused). As an example and not by way of limitation, the data acquisitionsystem may amplify, filter, or demodulate the signal. Various otherexamples of signal conditioning might be bridge completion, providingcurrent or voltage excitation to the sensor, isolation, time-basecorrection, and linearization. In particular embodiments, single-endedanalog signals may be converted to differential signals. In particularembodiments, digital signals may be encoded to reduce and correcttransmission errors or downsampled to reduce transmission powerrequirements.

Data Loving

In particular embodiments, the components of sensor network 100 mayutilize some type of data logging system to record, categorize, store,and file data from one or more data streams over time. The data loggingsystem may be local, for example, integrated into a sensor 112 in sensorarray 110 or into local analysis system 120. The data logging system mayalso be remote, for example, integrated into remote analysis system 150or an independent system. The data logging system may also usedistributed resources to record data. The data logging system may storedata on any suitable data store, such as, for example, data store 1740.

The data logging system may record data streams as one or more datasets. A data set comprises one or more data from a data stream. Datasets may be categorized and formed based on a variety of criteria. As anexample and not by way of limitation, a data stream could be recorded asone or more data sets based on the specific subject, sensor, timeperiod, event, or other criteria.

In particular embodiments, one or more data sets from a data stream maybe used to construct a binary decision diagram (BDD) representing thedata sets.

Data Aggregation

In particular embodiments, the components of sensor network 100 mayutilize a data aggregation system to process one or more data streamsfor use by analysis system 180 or display system 190. In particularembodiments, one or more nodes 114 may be data aggregation systems. Asan example and not by way of limitation, a data aggregation system maymonitor, synchronize, store, or analyze one or more data streams fromone or more sensors 112 in sensor array 110. As another example and notby way of limitation, the data aggregation system may analyze one ormore data streams from one or more sensors and generate one or morederivative data streams that may be synchronized, stored, andtransmitted.

In particular embodiments, the data aggregation system may access thedata streams from one or more sensors 112. A data stream from a sensor112 may be transmitted to a data aggregation system over any suitablemedium. As an example and not by way of limitation, a data aggregationsystem may be connected to one or more sensors by one or moreconnections 116. The data aggregation system may include one or moreconnection interfaces, such as, for example, a USB interface, a Firewireinterface, a 802.11 interface, a Bluetooth interface, another suitableconnection interface, or two or more such interfaces. Although thisdisclosure describes particular connection interfaces, this disclosurecontemplates any suitable connection interface.

In particular embodiments, a data aggregation system may access datastreams from one or more sensors 112 and synchronize the data streams.The data aggregation system may include one or more system clocks thatmay run synchronously or asynchronously of one or more other componentsin sensor network 100. In some embodiments, the system clock may beintegrated into the data aggregation system. In other embodiments, thesystem clock may reference one or more external time systems, such as aclock in sensor array 110, sensor 112, analysis system 180, displaysystem 190, or another suitable system. One or more sensors 112 may haveone or more sample frequencies or transmission frequencies. The samplefrequencies and transmission frequencies of a sensor 112 in sensor array110 may differ from the sample frequencies or transmission frequenciesof one or more other sensors 112 in sensor array 110. As an example andnot by way of limitation, a first data stream from a first sensor 112may comprise a tuple (s1, t1) representing a sample s1 with a localtimestamp t1 based on a local clock on the first sensor 112. A seconddata stream from a second sensor 112 may comprise a tuple (s2, t2)representing a sample s2 with a local timestamp t2 based on a localclock on the second sensor 112. If the first sensor 112 and the secondsensor 112 are not synchronized with each other, then samples s1 and s2may have been taken at the same absolute time even though timestamps t1and t2 are not the same value. In particular embodiments, the dataaggregation system may synchronize the first and second data streams byassociating a system timestamp with each sample based on a system clockintegrated into the data aggregation system. As an example and not byway of limitation, the data aggregation system may associate the systemtimestamp with each sample when the sample arrives at the dataaggregation system. The data aggregation system may assign the samples atimestamp t′ based on the system clock. The data aggregation system mayoverwrite the local timestamps, resulting in tuples (s1, t′) and (s2,t′), or the data aggregation system may add the timestamp t′ to thetuples, resulting in tuples (s1, t1, t′) and (s2, t2, t′). As anotherexample and not by way of limitation, the data aggregation system maysynchronize the local clocks on one or more sensors 112. The dataaggregation system may periodically broadcast the system clock time toconnected sensors 112. The connected sensors 112 may then adjust theirinternal clocks to match the broadcasted system clock's time. Theconnected sensors 112 may still sample and transmit data at frequenciesindependent of each other and of the data aggregation system, howeverwhen a connected sensor 112 takes a sample, it may associate the samplewith a system timestamp based on the connected sensor's 112 internalclock. In this manner, when the samples taken by the connected sensors112 reach the data aggregation system, the tuples will be (s1, t′) and(s2, t′). In particular embodiments, analysis of the data streams may bemore accurate and precise when the data streams are synchronized. As anexample and not by way of limitation, sensor array 110 may include anaccelerometer and a pulse oximeter. If the data streams from the twosensors are not synchronized, an analysis system 180 may not be able toaccurately determine correlations between blood-oxygen levels andactivity. Synchronizing data streams may allow more accurate analysis ofthe data streams for, in the case of this example, the causes of suddenblood-oxygen level changes. Although this disclosure describes a dataaggregation system synchronizing particular data streams in a particularmanner, this disclosure contemplates the data aggregation systemsynchronizing any suitable data streams in any suitable manner.

In particular embodiments, the data aggregation system may store thedata streams from one or more sensors 112. The data aggregation systemmay record the data streams and the system timestamps associated witheach of the samples. In particular embodiments, the data aggregationsystem may compress the data streams before storing. As an example andnot by way of limitation, the data aggregation system may store the datastreams with the system timestamps as one or more binary decisiondiagrams (BDDs). The data aggregation system may store the data streamswith the system timestamps in any suitable, tangible storage medium suchas, for example, an SD card, solid state device, hard drive, randomaccess memory, or memory integrated in a web server. Although thisdisclosure describes a data aggregation system storing data streams in aparticular manner, this disclosure contemplates the data aggregationsystem storing data streams in any suitable manner.

In particular embodiments, the data aggregation system may analyze oneor more data streams from one or more sensors 112 and generate one ormore derivative data streams that may be synchronized, stored, andtransmitted. The data aggregation system may perform an operation on oneor more data streams to generate a derivative data stream. As an exampleand not by way of limitation, the data aggregation system may use ameta-sensor that performs an operation on one or more data streams togenerate a derivative data stream. In particular embodiments, thederivative data stream may comprise samples that represent measurementsof stimuli not directly measured by the sensors 112 in sensor array 110.As an example and not by way of limitation, sensor array 110 may includean electrocardiogram and a pulse oximeter. The data aggregation systemmay use a meta-sensor to measure the time difference between theregistered heartbeat spikes on the data stream from theelectrocardiogram and on the data stream from the pulse oximeter togenerate a derivative data stream comprising blood pressure data. Inparticular embodiments, the blood pressure may be calculated with theformula:

$B = {{k_{1}{\ln\left( \frac{1}{p} \right)}} + k_{2}}$

where:

-   -   B is blood pressure,    -   k₁ is 159.6,    -   p is the pulse wave transit time, and k₂ is −51.2.        In other embodiments, the blood pressure may be calculated with        the formula:        B=k ₁exp(k ₂ p)

where:

-   -   B is blood pressure,    -   k₁ is 354.4    -   p is the pulse wave transit time, and    -   k₂ is −3.74.

In these formulas, the pulse wave transit time may be calculated fromthe time difference between heartbeat spikes on the data stream from theelectrocardiogram and on the data stream from the pulse oximeter. Inparticular embodiments, the data aggregation system may begin generatinga derivative data stream in response to the failure of one or moresensors 112 in sensor array 110. As an example and not by way oflimitation, sensor array 110 may include an electrocardiogram, a pulseoximeter, and a blood pressure monitor. If the blood pressure monitorfails or ceases to operate, the data aggregation system may use ameta-sensor to measure the time difference between the registeredheartbeat spikes on the data stream from the electrocardiogram and onthe data stream from the pulse oximeter to generate a derivative datastream comprising blood pressure data. The data aggregation system mayfurther synchronize, store, and transmit the derivative data streamcomprising blood pressure data. Although this disclosure describesparticular components performing particular processes to generate aderivative data stream, this disclosure contemplates any suitablecomponents performing any suitable processes to generate a derivativedata stream. Moreover, although this disclosure describes accessingparticular data streams to generate particular derivative data streams,this disclosure contemplates accessing any suitable data streams togenerate any suitable derivative data streams.

In particular embodiments, the data aggregation system may use thesystem timestamps associated with the samples to correlate one or moredata streams from sensors 112 with each other or with informationoutside the data streams. The data aggregation system may also transmitthe system timestamps with the results of correlating the original datastreams with each other or with information outside the data streams. Asan example and not by way of limitation, the data aggregation system mayindicate that a particular person's blood pressure increases duringholidays. As another example and not by way of limitation, the dataaggregation system may indicate that a particular person's heartbeatsbecome more irregular when the person's blood pressure is higher.Although this disclosure describes using system timestamps to correlatedata streams in a particular manner, this disclosure contemplates usingsystem timestamps to correlate data streams in any suitable manner.

In particular embodiments, the data aggregation system may transmit thedata streams or derivative data streams to one or more components ofsensor network 100. As an example and not by way of limitation, the dataaggregation system may transmit the data streams or derivative datastreams to analysis system 180, display system 190, or network 160 viaconnection 116. The data aggregation system may further transmit thesystem timestamps associated with the samples in the data streams orderivative data streams. As another example and not by way oflimitation, the data aggregation system may transmit the data streamsand derivative data streams across one or more portions of the Internet.In particular embodiments, the data aggregation system may transmit thedata streams or derivative data streams along with system timestampsassociated with the samples in the data streams or derivative datastreams.

In particular embodiments, the data aggregation system may transmit astart time and a sampling frequency with the results of correlating oneor more data streams from sensors 112 with each other or withinformation outside the data streams. The start time may represent theinitial time when sensors 112 began sampling. The start time mayrepresent the start time for the accessed data set. The samplingfrequency may represent the frequency at which sensors 112 sample orrecord data. In particular embodiments, a data aggregation system,analysis system 180, or display system 190 may analyze or display theresults of correlating the data streams by associating each data pointin the results with a timestamp. The timestamps may be based upon thestart time and the sampling frequency. As an example and not by way oflimitation, the second data point in the results may be assigned thetimestamp equal to the initial time plus the inverse of the samplingfrequency. As another example and not by way of limitation, the n^(th)data point in the results may be assigned a timestamp according to theformula:

$t_{s} = {t_{i} + {n\left( \frac{1}{v} \right)}}$

where:

-   -   t_(s) is the timestamp,    -   t_(i) is the initial time,    -   n is the n^(th) data point, and    -   v is the sampling frequency.

FIG. 6A illustrates an example system 600 comprising data aggregationsystem 614 and data flow to and from the data aggregation system 614.Data aggregation system 614 may receive data streams from one or moresensors 612. Data aggregation system 614 may operate on the input datastreams to generate and transmit one or more data streams. In particularembodiments, one or more sensors 612 may transmit data streams that areinputs into data aggregation system 614. As an example and not by way oflimitation, the data streams may comprise data about a person (or groupof persons or entities), place (such as, for example, a geographicallocation), or thing (such as, for example, a building, road, or car).Although this disclosure describes particular types of data streams,this disclosure contemplates any suitable types of data streams. Dataaggregation system 614 may receive one or more data streams as input andmay operate on them to generate one or more data streams. As an exampleand not by way of limitation, data aggregation system 614 maysynchronize the input data streams to generate one or more data streams.As another example and not by way of limitation, data aggregation system614 may perform a mathematical operation (such as, for example, additionor subtraction) on one or more data streams to generate a data stream.Although this disclosure describes particular types of operationsperformed on data streams, this disclosure contemplates any suitabletypes of operations. Data aggregation system 614 may transmit one ormore data streams as output. As an example and not by way of limitation,data aggregation system 614 may transmit the data streams to an analysissystem, display system, or network. Data aggregation system 614 maytransmit the data streams over a wired interface (such as, for example,a USB interface or a Firewire interface) a wireless interface (such as,for example, an 802.11 interface or a Bluetooth interface) anothersuitable interface, or two or more such interfaces. Although thisdisclosure describes particular types of transmission interfaces, thisdisclosure contemplates any suitable types of interfaces. Although FIG.6A illustrates a particular arrangement of sensors 612 and dataaggregation system 614, this disclosure contemplates any suitablearrangement of sensors 612 and data aggregation system 614. Moreover,although FIG. 6A illustrates a particular data flow between sensors 612and data aggregation system 614, this disclosure contemplates anysuitable data flow between sensors 612 and data aggregation system 614.

FIG. 6B illustrates an example system 600 comprising data aggregationsystem 614 and data flow to and from the data aggregation system 614.Data aggregation system 614 may receive data streams from one or moresensors 612. Data aggregation system 614 may include a meta-sensor 616that operates on one or more input data streams to generate a derivativedata stream. Meta-sensor 616 may use any suitable process, calculation,or technique to generate a derivate data stream. In particularembodiments, a derivative data stream may include data not directlymeasured by one or more sensors 612. Although FIG. 6B illustrates aparticular arrangement of sensors 612, data aggregation system 614, andmeta-sensor 616, this disclosure contemplates any suitable arrangementof sensors 612, data aggregation system 614, and meta-sensor 616.Moreover, although FIG. 6B illustrates a particular data flow betweensensors 612, data aggregation system 614, and meta-sensor 616, thisdisclosure contemplates any suitable data flow between sensors 612, dataaggregation system 614, and meta-sensor 616.

FIG. 7A illustrates an example of a data aggregation system 714. Inparticular embodiments, data aggregation system 714 comprises one ormore ports 730, a display 780, and a transmitter 760. One or more ports730 may be configured to receive data streams from one or more sensors.As an example and not by way of limitation, ports 730 may be USB ports,Firewire ports, another suitable port, or two or more such ports.Although this disclosure describes particular types of ports, thisdisclosure contemplates any suitable types of ports. Display 780 may beconfigured to display a data stream. In particular embodiments, display780 comprises a screen that displays a visual representation of a datastream. In other embodiments, display 780 comprises one or more lightemitting diodes displaying light patterns that represent a data stream.Although this disclosure describes particular types of displays, thisdisclosure contemplates any suitable type of display. Transmitter 760may be configured to transmit data streams to analysis systems, displaysystems, or networks. In particular embodiments, transmitter 760 maytransmit data streams over a wired interface (such as, for example, aUSB interface or a Firewire interface), a wireless interface (such as,for example, an 802.11 interface or a Bluetooth interface), anothersuitable interface, or two or more such interfaces. Although thisdisclosure describes particular transmission interfaces, this disclosurecontemplates any suitable transmission interface. In particularembodiments, data aggregation system 714 may further comprise a powercable 720 coupled to a power port 725, a data cable 740 coupled to aport 730, and a power button 750. Power cable 720 may supply electricpower to data aggregation system 714 through power port 725. Data cable740 may be the data transfer medium through which data streams travel toreach data aggregation system 714. In particular embodiments, data cable740 may be a USB cable, a Firewire cable, or another suitable cable.Although this disclosure describes particular types of data cables, thisdisclosure contemplates any suitable types of data cables. Power button750 may be configured to change the state of the data aggregation system714. In particular embodiments, power button 750 may, when pressed,change data aggregation system 714 from an “ON” state to an “OFF” state.In other embodiments, power button may, when pressed, change dataaggregation system 714 from an “ON” state to a “STANDBY” state. Althoughthis disclosure describes the data aggregation system operating inparticular states, this disclosure contemplates the data aggregationsystem operating in any suitable state. Although FIG. 7A describes aparticular arrangement of ports 730, display 780, transmitter 760, powercable 720, power port 725, data cable 740, and power button 750, thisdisclosure contemplates any suitable arrangement of ports 730, display780, transmitter 760, power cable 720, power port 725, data cable 740,and power button 750.

FIG. 7B illustrates an example of a data aggregation system 714. Inparticular embodiments, data aggregation system 714 comprises a receiverunit 735 comprising one or more ports 730, a processor unit 770comprising a synchronizer 771 and an operator 772, a storage unit 775,and a transmitter 760. Receiver unit 735 receives one or more datastreams at the one or more ports 730. As an example and not by way oflimitation, receiver unit 735 may be configured so that each port 730receives one data stream. In particular embodiments, each port 730comprises a data transfer interface. As an example and not by way oflimitation, port 730 may comprise a USB interface, Firewire interface,802.11 interface, or Bluetooth interface. Although this disclosuredescribes particular data transfer interfaces, this disclosurecontemplates any suitable data transfer interface. Processor unit 770may receive data streams from receiver unit 735 and may receive inputfrom storage unit 775. Processor unit 770 may output data streams totransmitter 760 and display 780. In particular embodiments, processorunit 770 may be a processor coupled to a memory. As an example and notby way of limitation, processor unit 770 may be a C64x processor or anARM processor. Although this disclosure describes particular types ofprocessors, this disclosure contemplates any suitable type of processor.In particular embodiments, processor unit 770 may comprise synchronizer771. Synchronizer 771 may synchronize the timestamps associated with thesamples in one or more data streams. Synchronizer 771 may use anysuitable process or technique to synchronize the timestamps. Inparticular embodiments, processor unit 770 may comprise operator 772.Operator 772 may operate on one or more data streams to generate aderivative data stream. Operator 772 may use any suitable process,calculation, or technique to generate a derivative data stream. Storageunit 775 may store one or more data streams received from processor unit770. Storage unit 775 may further store the timestamps associated withthe samples in one or more data streams. As an example and not by way oflimitation, storage unit 775 may comprise an SD card, solid statedevice, hard drive, random access memory, or memory integrated in a webserver. Although this disclosure describes particular types of storagedevices, this disclosure contemplates any suitable storage device. Inparticular embodiments, processor unit 770 may compress one or more datastreams before sending them to storage unit 775. As an example and notby way of limitation, storage unit 775 may store one or more datastreams and their associated timestamps as one or more binary decisiondiagrams (BDDs). Although this disclosure describes particular datacompression algorithms, this disclosure contemplates any suitable datacompression algorithm. In particular embodiments, storage unit 775 maysend stored data streams to processor unit 770. Transmitter 760 maytransmit data streams received from processor unit 770. Transmitter 760may transmit data streams to display systems 190, analysis systems 180,or networks 160. Transmitter 760 may transmit the data streams over awired interface (such as, for example, a USB interface or a Firewireinterface), a wireless interface (such as, for example, an 802.11interface or a Bluetooth interface), another suitable interface, or twoor more such interfaces. Although this disclosure describes particulartypes of transmission interfaces, this disclosure contemplates anysuitable types of interfaces. In particular embodiments, dataaggregation system 714 further comprises a display 780. Display 780 maydisplay data streams received from processor unit 770 in a visualformat. As an example and not by way of limitation, display 780 maydisplay a data stream as a graph, chart, or table. Although thisdisclosure describes particular visual formats, this disclosurecontemplates any suitable visual format. In particular embodiments, dataaggregation system 714 further comprises a battery 725. Battery 725 maysupply electric power to the elements of data aggregation system 714. Asan example and not by way of limitation, battery 725 may supply electricpower to receiver unit 735, processor unit 770, storage unit 775,transmitter 760, and display 780. In particular embodiments, battery 725may be rechargeable. Battery 725 may comprise a recharging interfacethat receives electric power from an external source. As an example andnot by way of limitation, battery 725 may comprise an interface toreceive a power cable 720. Although FIG. 7B describes a particulararrangement of ports 730, receiver unit 735, processor unit 770,synchronizer 771, operator 772, display 780, transmitter 760, storageunit 775, and battery 725, this disclosure contemplates any suitablearrangement of ports 730, receiver unit 735, processor unit 770,synchronizer 771, operator 772, display 780, transmitter 760, storageunit 775, and battery 725. Moreover, although FIG. 7B illustrates aparticular data flow within data aggregation system 714, this disclosurecontemplates any suitable data flow within data aggregation system 714.

FIG. 8 illustrates an example method 800 for synchronizing data streams.The method begins at step 810, where a mobile computing device accessesan original data stream from each of one or more sensors. The mobilecomputing device may be a data aggregation system 614 or 714, a node114, or another suitable system. Each of the original data streams maycomprise a series of samples that each represent a measurement of astimulus sensed by the sensors that the original data stream is from.One or more of the sensors may be affixed to a person's body. At step820, the mobile computing device associates a system timestamp with eachof the samples based on a system clock. The system clock may operateindependently of the sensors. At step 830, the mobile computing devicerecords the original data streams with the system timestamps associatedwith their samples. This may be used for correlation of the originaldata streams with each other or with information outside the datastreams. Although this disclosure describes particular compressionalgorithms, this disclosure contemplates any suitable compressionalgorithm. Although this disclosure describes and illustrates particularsteps of the method of FIG. 8 as occurring in a particular order, thisdisclosure contemplates any suitable steps of the method of FIG. 8occurring in any suitable order. Moreover, although this disclosuredescribes and illustrates particular components carrying out particularsteps of the method of FIG. 8, this disclosure contemplates any suitablecombination of any suitable components carrying out any suitable stepsof the method of FIG. 8.

Analysis

Analysis system 180 may monitor, store, and analyze one or more datastreams from one or more sensors 112 or from one or more nodes 114 insensor array 110. A data stream from a sensor 112 or a node 114 may betransmitted to analysis system 180 over any suitable medium. Analysissystem 180 may transmit one or more analysis outputs based on the one ormore data streams to one or more other components of sensor network 100,such as, for example, sensors 112, nodes 114, other analysis systems180, or display systems 190. Analysis system 180 may be any suitablecomputing device, such as, for example, computer system 1600.

In particular embodiments, analysis system 180 may comprise one or morelocal analysis systems 120 or one or more remote analysis systems 150.Where analysis system 180 comprises multiple subsystems (e.g., localanalysis system 120 and remote analysis system 150), processing andanalysis of the data streams may occur in series or in parallel. As anexample and not by way of limitation, analysis system 180 may receiveidentical data streams from a sensor 112 at both local analysis system120 and remote analysis system 150. As another example and not by way oflimitation, analysis system 180 may receive a data stream at localanalysis system 120, which may process the data stream and then transmita modified data stream/analysis output to remote analysis system 150.

In particular embodiments, analysis system 180 may access and analyzeone or more data sets from a data stream. Analysis system 180 mayanalyze a data stream in real-time as it is received from sensor array110, or it may store the data stream after it is received from sensorarray 110 for subsequently process the data stream. Analysis system 180may use any suitable process, calculation, or technique to analyze adata stream. As an example and not by way of limitation, analysis system180 may perform a variety of processes and calculations, includingranging, inspecting, cleaning, filtering, transforming, modeling,normalizing, averaging, annotating, correlating, or contextualizingdata. As another example and not by way of limitation, analysis system180 may use a variety of data analysis techniques, including datamining, data fusion, distributed database processing, or artificialintelligence. These techniques may be applied to analyze various datastreams and to generate correlations and conclusions based on the data.Analysis system 180 may analyze a plurality of data streams to determineif the data streams are related. A relationship between data streams mayinclude, for example, correlations, causal relationships, dependentrelationships, reciprocal relationships, data equivalence, anothersuitable relationship, or two or more such relationship. Although thisdisclosure describes analysis system 180 performing particularanalytical processes using particular techniques, this disclosurecontemplates analysis system 180 performing any suitable analyticalprocesses using any suitable techniques.

Modeling Data Streams

In particular embodiments, analysis system 180 may generate models basedon one or more data streams. A model is a means for describing a systemor object. As an example and not by way of limitation, a model may be adata set, function, algorithm, differential equation, chart, table,decision tree, binary decision diagram, simulation, another suitablemodel, or two or more such models. A model may describe a variety ofsystems or objects, including one or more aspects of one or morepersons' physiology, psychology, behavior, or environment. Although thisdisclosure describes particular components generating particular models,this disclosure contemplates any suitable components generating anysuitable models. Moreover, although this disclosure describes generatingparticular models using particular techniques, this disclosurecontemplates generating any suitable models using any suitabletechniques.

Analysis system 180 may generate models that are empirical, theoretical,linear, nonlinear, deterministic, probabilistic, static, dynamic,heterogeneous, or homogenous. Analysis system 180 may generate modelsthat fit one or more data points using a variety of techniques,including, for example, curve fitting, model training, interpolation,extrapolation, statistical modeling, nonparametric statistics,differential equations, etc.

Analysis system 180 may generate models of various types, includingbaseline models, statistical models, predictive models, etc. A baselinemodel is a model that serves as a basis for comparison, and is typicallygenerated using controlled data (i.e., baseline data) over a specifiedperiod (i.e., a control period). The control period may be any suitableperiod. As an example and not by way of limitation, a baseline model ofa subject's blood pressure may simply be the subject's average bloodpressure calculated from a series of blood-pressure measurements takenover the course of a week by a blood-pressure monitor. A predictivemodel is a mathematical function (or set of functions) that describe thebehavior of a system or object in terms of one or more independentvariables. As an example and not by way of limitation, a predictivemodel that may be used to calculate a physiological state based on oneor more actual sensor measurements. A type of predictive model is astatistical model, which is a mathematical function (or set offunctions) that describe the behavior of an object of study in terms ofrandom variables and their associated probability distributions. One ofthe most basic statistical models is the simple linear regression model,which assumes a linear relationship between two measured variables. Asan example and not by way of limitation, analysis system 180 may comparedata from a pulse oximeter and a barometer and identify a linearcorrelation between a subject's blood-oxygen level and the barometricpressure at the subject's location. In particular embodiments, apredictive model may be used as a baseline model, wherein the predictivemodel was generated using controlled data over a specified period.

In particular embodiments, analysis system 180 may generate a model bynormalizing or averaging one or more data streams. As an example and notby way of limitation, a model of a data stream from a single sensor 112could simply be the average sensor measurement made by the sensor 112over some initialization period. As another example and not by way oflimitation, a model could be a single sensor 112 measurement made duringa control period.

In particular embodiments, analysis system 180 may generate a model byfitting one or more data sets to a mathematical function. As an exampleand not by way of limitation, a model could be an algorithm based onsensor measurements made by one or more sensors over some controlperiod. The model may include a variety of variables, including datafrom one or more data streams and one or more fixed variables. Thefollowing is an example algorithm that analysis system 180 couldgenerate to model a system or object:f _(m) =f(D _(sensor) ¹ , . . . ,D _(sensor) ^(N) ,Y ¹ , . . . ,Y ^(M))

where:

-   -   f_(m) is the model,    -   (D_(sensor) ¹, . . . , D_(sensor) ^(N)) are data streams 1        through N, and    -   (Y¹, . . . , Y^(M)) are fixed variables 1 through M.

In particular embodiments, the model may be used to predict hypotheticalsensor measurements in theoretical or experimental systems. Inparticular embodiments, the model may be used to determine or categorizea subject's physiological or psychological state. As an example and notby way of limitation, the model may determine a subject's risk for acertain disease state with an abstract or statistical result. The modelcould simply identify the subject as being at “high risk” of developinga disease, or identify the subject as being 80% likely to develop thedisease. As another example and not by way of limitation, the model maydetermine a subject's severity or grade of a disease state.

Contextualizing and Correlating Data Streams

In particular embodiments, analysis system 180 may map one or more datastreams over time, allowing the data streams to be compared. Mapping andcomparing the data streams allows analysis system 180 to contextualizeand correlate a data set from one data stream with data sets from one ormore other data streams.

In particular embodiments, analysis system 180 may analyzephysiological, psychological, behavioral, or environmental data steamsto contextualize one data set with another data set. Contextualizing isthe process of interpreting a data set against the background ofinformation provided by one or more data streams. As an example and notby way of limitation, a user may be wearing a heart-rate monitor and anaccelerometer, which transmit a heart-rate data stream and anaccelerometer data stream, respectively. A data set in the heart-ratedata stream may show the user had an elevated heart-rate during acertain time period. Analysis system 180 may contextualize theheart-rate data by mapping the heart-rate data against data from anaccelerometer data stream that shows that the user had an elevatedactivity during the same time period. A data set may be contextualizedusing data from a data stream from a sensor 112 or from fixed dataaccessed by analysis system 180. As another example and not by way oflimitation, a data set of a user's heart rate from a heart-rate monitormay be contextualized against a data set of the user's genome.

In particular embodiments, analysis system 180 may analyzephysiological, psychological, behavioral, or environmental data steamsto identify correlations between certain data sets. Correlating isestablishing or demonstrating a causal, complementary, parallel, orreciprocal relation between one data set and another data set. As anexample and not by way of limitation, there is a positive correlationactivity level in a person and the heart rate of the person. Analysissystem 180 may analyze heart-rate data and accelerometer data andestablish that when a user increases his activity beyond a certainlevel, it will cause an increase in his heart-rate and that activitylevel and heart-rate will increase proportionally until the user'sheart-rate reaches a certain rate. The degree of correlation is thedegree to which two or more measurements change simultaneously. Thesecorrelations may be of varying degrees of dependence (e.g., asdetermined by a Pearson's product-moment coefficient). In general,analysis system 180 may make more accurate correlations as more databecomes available from sensor array 110. Analysis system 180 may thenuse these correlations to generate causality hypotheses of varyingdegrees of confidence. In general, analysis system 180 may make moreaccurate correlations as more data becomes available from sensor array110.

In particular embodiments, analysis system 180 may contextualize andcorrelate a data set from one or more data streams that exhibits sometype of deviation, variability, or change. The deviation, variability,or change in a data stream may be with respect to other data sets in thedata stream or with respect to other data streams. By mapping andcomparing data streams that exhibits some type of deviation,variability, or change, analysis system 180 may contextualize andcorrelate the data streams. This may be useful, for example, to identifythe cause of a deviation, variability, or change in a data stream. As anexample and not by way of limitation, an elevated heart-rate thatcoincides with increased activity is typically a normal response.However, a spike in heart-rate that coincides with a marginal elevatedphysical activity may not be a normal response. Analysis system 180could then determine, based on the comparison, whether certain levels ofactivity produce abnormal heart-rate spikes in the user.

As an example and not by way of limitation, sensor array 110 may includea heart-rate sensor, a mood sensor 400 (for collecting subjective stressand behavior information) that is a smart phone, and a GPS system thatis built into the smart phone. This system may be used to contextualizeand correlate physiological, psychological, behavioral and environmentaldata streams to diagnose and monitor stress in a user. For example, theheart-rate sensor's data stream may show a spike in the user'sheart-rate at certain times of the day or at certain locations.Similarly, mood sensor 400's data stream, when mapped against theheart-rate data, may show these time periods of increased heart-ratecorrelate to periods when the user indicated that his mood was“stressed” and his activity was “driving.” If the user has previouslybeen diagnoses as hypertensive, it may be desirable to avoid theseparticularly stressful driving situations that cause a spike in theuser's heart-rate. These stressful driving situations may be identifiedby contextualizing the prior data streams against the GPS system's datastream. When the location data from the GPS system is mapped against theprior data streams, it may show the heart-rate spikes, stressed mood,and driving, all occurred at a specific highway interchange. Therefore,by contextualizing the physiological, psychological, behavioral, andenvironmental data streams, analysis system 180 may identify driving onthe specific highway interchange as the cause of the user's heart-ratespikes. This could be useful, for example, to allow the user to identifysituations to avoid (e.g., the specific highway interchange) andpossibly to identify better or healthier alternatives (e.g., takingsurface streets).

Diagnosis and Monitoring of Health States

In particular embodiments, one or more sensors 112 or one or more nodes114 in sensor array 110 may continuously transmit data regarding asubject's health to analysis system 180, which may monitor andautomatically detect changes in the subject's health state. As usedherein, “health state” refers to a person's physiological andpsychological state, including the person's state with respect topathologies and diseases. By using an integrated sensor array 110 tomonitor physiological, psychological, behavioral, and environmentaldata, analysis system 180 may identify pathologies, disease states,sensitivities, and other health-related states with greater accuracythan is possible with any individual sensor 112.

In particular embodiments, one or more sensors 112 in sensor array 110may measure one or more biomarkers. A biomarker is a characteristic thatcan be measured and evaluated as an indicator of biological processes,pathogenic processes, or pharmacologic responses. As an example and notby way of limitation, in a pharmacogenomic context, a biomarker would bea specific genetic variation that correlates with drug response. Asanother example and not by way of limitation, in a neurochemicalcontext, a biomarker would be a person's subjective stress level thatcorrelates with the person's plasma glucocorticoid level. As yet anotherexample and not by way of limitation, in a neuropsychological context, abiomarker would be a person's serotonin uptake rate that correlates withthe person's depression level. As yet another example and not by way oflimitation, in a biochemical context, a biomarker would be a person'sLDL cholesterol level that correlates with the person's risk of heartdisease, such as heart attack. A biomarker is effectively a surrogatefor measuring another physiological or psychological characteristic. Abiomarker may include any type of stimulus, including physiological,psychological, behavioral, or environmental stimulus.

In particular embodiments, analysis system 180 may identify pathologies,disease states, and other health states of a subject. Certainphysiological, psychological, behavioral, or environmental data maycorrelate with certain pathologies, disease states, and other healthstates. As an example and not by way of limitation, analysis system 180could determine whether a subject has hypertension by monitoring ablood-pressure data stream for a three-week period and identifyingsubstantial periods where the subject's blood pressure is at least140/90 mmHg, wherein these substantial periods of elevated bloodpressure constitute hypertension. The accuracy of identification maygenerally be increased as the number of data streams is increased.Analysis system 180 may contextualize and correlate data from multipledata streams to eliminate confounders from its data analysis and reducethe likelihood of generating false-positive and false-negativedisease-state diagnoses. As an example and not by way of limitation, thehypertension diagnosis system described above may generate afalse-positive diagnosis of hypertension if the subject engages inlengthy periods of physical activity, which naturally raise thesubject's blood pressure. Therefore, if analysis system 180 alsomonitored a heart-rate data stream of the subject, it could eliminateblood pressure data sets that correlate with time periods of highheart-rate, thereby reducing the likelihood of generating an incorrecthypertension diagnosis.

In particular embodiments, analysis system 180 may analyzephysiological, psychological, behavioral, or environmental data steamsto identify correlations between certain data sets and a subject'shealth state. As an example and not by way of limitation, analysissystem 180 may be able to correlate a behavioral data set indicating thesubject had a fight with a physiological data set indicating the subjecthad an elevated heart-rate to identify the fight as the cause of theelevated heart-rate. As another example and not by way of limitation,analysis system 180 may be able to correlate a physiological data setindicating the subject had an elevated skin-temperature with abehavioral data set indicating the subject was engaged in physicalactivity to identify the physical activity as the cause of the elevatedskin-temperature. As yet another example and not by way of limitation,analysis system 180 may be able to correlate a psychological data setindicating the subject is depressed with an environmental data setindicating that the subject's stock portfolio substantially declinedjust prior to the onset of the subject's depression to identify thestock decline as the cause of the subject's depression. Analysis system180 may use a variety of methods to identify correlations and generatecausality hypotheses.

In particular embodiments, analysis system 180 may generate a model of asubject's health state. As an example and not by way of limitation,analysis system 180 may generate a baseline model of the subject'sphysiological or psychological state by analyzing one or more datastreams during a control period. Once the baseline model is established,analysis system 180 could then continuously monitor the subject andidentify deviations, variability, or changes in the data streams ascompared to the baseline model. As another example and not by way oflimitation, analysis system 180 may generate a predictive model of thesubject's physiological or psychological state by analyzing one or moredata streams and generating one or more algorithms that fit the sensormeasurements. Once the predictive model is established, analysis system180 could then be used to predict future health states, anticipated orhypothetical sensor readings, and other aspects of a subject'sphysiology or psychology. Analysis system 180 may also update and refinethe predictive model based on new data generated by sensor array 110.

In particular embodiments, analysis system 180 may monitor disease-stateprogression and other health state changes over time. As an example andnot by way of limitation, analysis system 180 could continuously monitora subject's blood pressure over time to determine whether the subject'shypertension is improving. Such monitoring may be used to identifytrends and to generate alerts or predictions regarding possible healthstates. Similarly, analysis system 180 may also monitor data streamscontaining treatment or therapy information to determine whether thetreatment or therapy is efficacious. As an example and not by way oflimitation, analysis system 180 could monitor a subject's blood pressureover time to determine whether an ACE inhibitor treatment is affectingthe subject's hypertension.

In particular embodiments, analysis system 180 may monitor and analyzevarious data streams from a group of people to identify novelpre-disease states or risk states. As an example and not by way oflimitation, one or more sensor arrays 110 could monitor a plurality ofsubjects. As multiple subjects develop certain diseases, analysis system180 could analyze data sets from these subjects prior their developmentof the disease. The analysis of these data sets could allow analysissystem 180 to identify certain health states that correlate with somelevel of risk for developing the disease.

Stress Generally

Stress is a person's total response to environmental demands orpressures. Stress is a state which arises from an actual or perceiveddemand-capability imbalance in a person. It is a negative emotionalexperience accompanied by biochemical, physiological, and behavioralchanges that are directed either toward altering the stressful event oraccommodating it. Stress results from interactions between a person andthe environment that are perceived as straining or exceeding theperson's adaptive capacities and threatening their well-being. Thecauses of stress (i.e., stressors) may include any event or occurrencethat a person considers a threat to his coping strategies or resources.Stress may cause a variety of physiological, psychological, orbehavioral reactions in a person. As an example and not by way oflimitation, stress may cause a person's body to release certain hormonesand neurotransmitters, such as catecholamines and glucocorticoids.

Catecholamines are neurotransmitters in the sympathetic nervous system.Catecholamines are synthesized from tyrosine. They are also releasedinto the blood during times of psychological or physiological stress.High catecholamine levels in blood are associated with stress. The majorcatecholamines are dopamine, norepinephrine (noradrenaline), andepinephrine (adrenaline). Catecholamines are synthesized in the brainand other neural tissue. Catecholamines are also produced by the adrenalglands and secreted into the blood. Norepinephrine and dopamine act asneuromodulators in the central nervous system and as hormones in theblood circulation. Norepinephrine is a neuromodulator of the peripheralsympathetic nervous system but is also present in the blood (mostlythrough “spillover” from the synapses of the sympathetic system).Catecholamines may cause general physiological changes that prepare thebody for physical activity (“fight-or-flight” response). Some typicaleffects include increases in heart rate, blood pressure, blood glucoselevels, and increased activity of the sympathetic nervous system. Somedrugs, like tolcapone (a central COMT-inhibitor), raise the levels ofall the catecholamines by blocking their degradation post-release.

Epinephrine is an important catecholamine that acts primarily on muscle,adipose tissue, and the liver. Epinephrine increases delivery of O₂ tomuscle tissue by increasing heart rate and blood pressure, and dilatingrespiratory passages. Epinephrine increases production of glucose byactivating glycogen phosphorylase and inactivating glycogen synthase,thus simulating gluconeogenesis in the liver. Epinephrine promotes theanaerobic breakdown of glycogen in skeletal muscle into lactate byfermentation, thus stimulating glycolytic ATP formation. The stimulationof glycolysis is accomplished by raising the concentration of fructose2,6-bisphosphate, an allosteric activator of the glycolytic enzymephosphofructokinase-1. Finally, epinephrine stimulates glucagonsecretion and inhibits insulin secretion.

Glucocorticoids are a class of steroid hormones that bind to theglucocorticoid receptor. Glucocorticoids have many diverse (pleiotropic)effects, including potentially harmful effects. Glucocorticoids causetheir effects by binding to the glucocorticoid receptor. The activatedglucocorticoid receptor complex up-regulates the expression ofanti-inflammatory proteins in the nucleus (a process known astransactivation) and represses the expression of pro-inflammatoryproteins in the cytosol by preventing the translocation of othertranscription factors from the cytosol into the nucleus(transrepression).

Cortisol (or hydrocortisone) is the most important human glucocorticoid.It is essential for life, and it regulates or supports a variety ofimportant cardiovascular, metabolic, immunologic, and homeostaticfunctions. A variety of stressors (anxiety, fear, pain, hemorrhage,infections, low blood glucose, etc.) stimulate release of cortisol fromthe adrenal cortex. Cortisol acts on muscle, liver, and adipose tissueto supply the person with fuel for impending intense activity. Cortisolis a relatively slow-acting hormone that alters metabolism by changingthe kinds and amounts of certain enzymes that are newly synthesized inits target cell, rather than by regulating existing enzyme molecules. Inadipose tissue, cortisol stimulates the release of fatty acids fromstored triacylglycerols. The fatty acids are exported to the blood toserve as fuel for various tissues, and the glycerol resulting fromtriacylglycerol breakdown is used for gluconeogenesis in the liver.Cortisol stimulates the breakdown of nonessential muscle proteins andthe export of amino acids to the liver where they serve as precursorsfor gluconeogenesis. In the liver, cortisol promotes gluconeogenesis bystimulating synthesis of the key enzyme PEP carboxykinase; glucagon alsohas this effect, whereas insulin has the opposite effect. Glucoseproduced in this way is stored in the liver as glycogen, or exportedimmediately by tissues that need glucose for fuel. The net effect ofthese metabolic changes is to elevate blood glucose levels and to storeglycogen to support the fight-or-flight response commonly associatedwith stress. Consequently, the effects of stress hormones, such ascortisol, may counterbalance those of insulin.

Symptoms of stress may be psychological, physiological, or behavioral.Symptoms include poor judgment, depression, anxiety, moodiness,irritability, agitation, loneliness, various muscle complaints,headaches, diarrhea or constipation, nausea, dizziness, chest pain,elevated heart-rate, irregular eating, irregular sleeping, socialwithdrawal, procrastination or neglect of responsibilities, drug andalcohol abuse, and other abnormal or irregular behaviors.

Measuring Stress

In particular embodiments, sensor network 100 may analyze physiological,psychological, behavioral, or environmental data streams to diagnose andmonitor stress in a user. Sensor array 110 may intermittently orcontinuously transmit physiological, psychological, behavioral, orenvironmental data streams to analysis system 180. Analysis system 180may analyze one or more of these data streams to determine the stressindex of the user. Any combination of two or more sensors may be used togenerate a stress index value. These stress index values may be improvedand calibrated by monitoring a person over time to determine when achange in physiological state is due to stress or due to a non-stressrelated event (such as, for example, exercise, dehydration). Thestress-induced physiological changes may be used to establish a baselinephysiological state for a person and a range of physiological variationassociated with stress. A person may also engage in a training orcontrol period during which the person's input or feedback may be usedto engage machine-learning algorithms to develop a stress model thatallows the person's stress index to be calculated. Similarly, machinelearning may be used to correlate physiological stress responses withchanges in psychological, behavioral, or environmental state.

In particular embodiments, analysis system 180 may access physiological,psychological, behavioral, or environmental data previously generated tocompare it to current physiological, psychological, behavioral, orenvironmental data. Analysis system 180 may also access a stress indexpreviously determined to compare it to a current stress index. Based onthe comparison, analysis system 180 may then determine whether theuser's stress level has changed over time. Analysis system 180 may alsomodel the stress level with respect to time and identify any trends inthe stress level of the user. Based on these changes and trends instress level, various alerts or warnings may be provided to the user orto a third-party (e.g., the user's physician).

Analysis system 180 may use a variety of scales, both qualitative andquantitative, for assessing the stress level in a person. The stresslevel of a person may be quantified using a stress index, which may beany suitable scale for measuring or valuing stress. Analysis system 180may quantify stress by combining data from multiple sensors 112. Thesimplest approach would be to assign a single numerical value, i.e., astress index. Further refinements could be developed, such as, forexample, a transient stress index, a stress load, a stress-resiliencecoefficient, or other suitable stress measurements. As an example andnot by way of limitation, analysis system 180 could grade the stresslevel of a person on a 0-to-4 Liker scale, where the five-level Likertitem may be:

0. Very unstressed

1. Moderately unstressed

2. Neither stressed nor unstressed

3. Moderately stressed

4. Very stressed

Other suitable Likert items may be used. The Likert items may beanalyzed as interval-level data or as ordered-categorical data. Asanother example and not by way of limitation, analysis system 180 couldgrade the stress level of a person on a scale of 0 to 100, where 0 isthe user's baseline stress when relaxed and resting and 100 is theuser's maximum stress. A stress index may be scaled on an absolute scaleor scaled on an individual scale. As an example and not by way oflimitation, two users experiencing the same stress experience wouldreport identical stress levels on an absolute stress index. However, twousers experiencing the same stress experience may report differentstress levels on individual stress indexes. A first user's baselinestress when relaxed may report a stress index of 0, which is differentfrom a second user's baseline stress when relaxed and may also report astress index of 0. Similarly, a first user may only have a minor stressresponse to a particular stress while a second user may have a majorstress response to the same stressor. In particular embodiments, astress index may be a multidimensional index. As an example and not byway of limitation, the stress index may quantify a person's transientstress (i.e., the change in stress caused by a stressor), baselinestress (i.e., the person's stress when in a normal state), and stressresilience (i.e., the rate at which a patient recovers from a stressor).In particular embodiments, a stress factor may be assigned to particularstressor or therapy. A stress factor is the change in a person's stressindex associated with a particular stressor or therapy. As an exampleand not by way of limitation, driving in traffic may increase a person'sstress index by 10 points on a 0-to-100 stress scale, while doing deepbreathing exercises may decrease the person's stress index by 8 points.Although this disclosure describes particular stress indexes usingparticular scales for assessing the stress level in a person, thisdisclosure contemplates any suitable stress indexes using any suitablescales for assessing the stress level in a person.

Stress may be measured using a variety of methods. As an example and notby way of limitation, stress may be measured by analyzing heart-ratevariability, stress-related analytes, and self-reported subjectivestress.

Stress may be measured by accessing data from a heat-rate monitor andanalyzing heart-rate variability. Heart-rate variability is typicallymeasured using a pulse oximeter, which may measure the heart rate andblood oxygenation levels of a person. The basic technique of quantifyingstress by using heart-rate variability and associating differentfrequency bands with activation of the sympathetic and parasympatheticsystems comes from work in the 1980's (e.g., Pagani et al., 1986). Bycreating a ratio of the two frequency bands, a quantitative measure(“sympathovagal balance” (Pagani et al., 1986; Bigger et al., 1992))comparing the relative activations is created, which the literaturerepresents as the stress level of the person. This idea is refined to bemore robust to signal noise and is described more fully in laterliterature (Albrecht & Cohen, 1988; Rottman et al., 1990; Bigger et al.,1992). Parati et al. (1995) provides a survey of spectral analysisapplied to HRV and blood pressure variability. They include somereasoning for the choice of HF (parasympathetic control) being definedas frequencies above 0.15 Hz. and LF (sympathetic control) being definedas frequencies below 0.15 Hz (but likely above 0.07 Hz). They also notethat these measures incompletely account for the actions of thesympathetic and parasympathetic systems, so that the ratio measure givea value that we associate with high stress but is actually due to someother phenomenon. A detailed discussion of the difficulty in measuringheart-rate variability can be found in Clifford (2002).

Stress may also be measured by accessing data from a biosensor andanalyzing stress-related analyte levels, such as glucocorticoid andcatecholamine levels. Various means may be used to measureglucocorticoid and catecholamine levels, including immunoassays andvarious chromatography techniques. The biosensors may measure andtransmit information regarding the user's analyte levels. Analysissystem 180 may then analyze this analyte data by inputting it into astress model that correlates stress-related analyte levels with stressto calculate the user's stress index.

Stress may also be measured by accessing self-reported stressinformation, such as, for example, from one or more user-input sensorsthat may receive information on a user's subjective experience ofstress. A user's psychological stress may be a biomarker for the user'sphysiological stress response. The user's subjective experience ofstress may be used to indirectly measure the user's physiologicalstress, for example, by correlating the user's subjective experience ofstress with the user's glucocorticoid level. The user-input sensor maymeasure and transmit information regarding the user's psychologicalstress levels. Analysis system 180 may then analyze this psychologicaldata by inputting it into a stress model that correlates psychologicalstress levels with stress to calculate the user's stress index.

Although this disclosure describes particular methods for measuringstress, this disclosure contemplates any suitable methods for measuringstress. As an example and not by way of limitation, stress may bemeasured using any suitable data streams from physiological,psychological, behavioral, or environmental sensors.

Creating a Personalized Stress Profile Using Renal Doppler Sonography

Measuring and monitoring stress is a major challenge for presentdevices. The physiological response to stress may vary from person toperson in type as well as extent. This causes a problem in creating ageneralized method for measuring and monitoring stress in humans. Themajor changes during stress are observed in the sympathetic nervoussystem. The sympathetic nervous system is responsible for up- anddown-regulating many homeostatic mechanisms in living organisms. Fibersfrom the sympathetic nervous system innervate tissues in almost everyorgan system, providing at least some regulatory function to things asdiverse as pupil diameter, gut motility, and urinary output. It isperhaps best known for mediating the neuronal and hormonal stressresponse. Therefore, one method of measuring stress may involvemeasuring and monitoring the response of sympathetic nerves, such as inthe kidney, where such nerves are rich.

The kidneys serve essential regulatory roles in most animals, includingvertebrates and some invertebrates. They are essential in the urinarysystem and also serve homeostatic functions (such as, for example, theregulation of electrolytes, maintenance of acid-base balance, andregulation of blood pressure). The kidneys serve the body as a naturalfilter of the blood, and remove wastes which are diverted to the urinarybladder. In producing urine, the kidneys excrete wastes such as urea andammonium; the kidneys also are responsible for the reabsorption ofwater, glucose, and amino acids. The kidneys also produce hormonesincluding calcitriol, renin, and erythropoietin. Located at the rear ofthe abdominal cavity in the retroperitoneum, the kidneys receive bloodfrom the paired renal arteries, and drain into the paired renal veins.Each kidney excretes urine into a ureter, itself a paired structure thatempties into the urinary bladder.

The kidney participates in whole-body homeostasis by regulatingacid-base balance, electrolyte concentrations, extracellular fluidvolume, and blood pressure. The kidney accomplishes these homeostaticfunctions both independently and in concert with other organs (i.e.,both extra-renal and intra-renal mechanisms), particularly those of theendocrine system. Various endocrine hormones coordinate these endocrinefunctions, such as, for example, renin, angiotensin II, aldosterone,antidiuretic hormone, and atrial natriuretic peptide.

Many of the kidney's functions are accomplished by relatively simplemechanisms of filtration, reabsorption, and secretion, which take placein the nephron. Filtration, which takes place at the renal corpuscle, isthe process by which cells and large proteins are filtered from theblood to make an ultrafiltrate that eventually becomes urine. Thetypical human kidney generates 180 liters of filtrate a day, whilereabsorbing a large percentage, allowing for only the generation ofapproximately 2 liters of urine. Reabsorption is the transport ofmolecules from this ultrafiltrate and into the blood. Secretion is thereverse process, in which molecules are transported in the oppositedirection, from the blood into the urine.

The sympathetic nervous system is an integral part of the homeostaticcontrol system that maintains normal kidney function, with an extensivenetwork of nerves identified in most renal tissues. The sympatheticnervous system modulates short-term regulation of renal function, andunder normal conditions renal sympathetic nerve activity is low. Duringacute stress, however, elevated renal sympathetic activity depressesrenal function. Chronic stress studies have been less conclusive and aredifficult to design due to additional pathologies induced by stress,such as hypertension and cardiovascular complications. Major renaleffects of mental stress include increased renal vasoconstriction,causing greater renal vascular resistance (RVR), and increased Na⁺transport, causing greater Na⁺ retention. Both of these effects maycontribute to the development of hypertension, and some investigatorspropose that this may be the primary mechanism of hypertension.Therefore, most studies on the renal effects of stress have focused onits relationship to hypertension. Though the effects of stress are morepronounced in hypertensive subjects, stress increases renalvasoconstriction and Na⁺ retention in normal subjects as well.

The systemic blood pressure determines the renal perfusion pressure(RPP) and is a major determinant of renal vascular resistance. Thekidney has a unique ability to efficiently auto-regulate its own bloodflow over a wide range of renal perfusion pressures. Renal blood flow(RBF) changes very little over a large range of renal perfusionpressures, thus helping to maintain a stable renal vascular resistance.This is due to the fine control of vascular tone in the primary renalresistance vessels, the pre-glomerular afferent arterioles, and thepost-glomerular efferent arterioles. However, many hormonal and neuraldisturbances can alter auto-regulation, often targeting thesearterioles, leading to inappropriate increases in renal vascularresistance. Increased sympathetic activity increases arteriolarresistance and renal vascular resistance. Increased renal vascularresistance exacerbates hypertension via its contribution to overallincreased total peripheral resistance (since renal blood flow is 20-25%of cardiac output) and its ability to promote Na⁺ reabsorption. Stresscan induce both neural and hormonal changes that affect renal vascularresistance.

Renal blood flow correlates with stress and therefore changes in renalblood flow may be significant indicators of stress. A user's stresslevel may be determined from renal blood flow information. Changes in aperson's renal resistive index or renal vascular resistance may be usedto detect the person's physiological or psychological responses tostress. As an example and not by way of limitation, a higher renalresistive index (renal RI) corresponds to a higher stress level.Similarly, a lower renal RI corresponds to a lower stress level (i.e., arelaxed state). Renal blood flow information may then be used togenerate or validate stress models. Doppler sonography (pulse orcontinuous) may be used to measure the renal arterial blood flow. Arenal Doppler sonograph may also include information about the peakblood pulse. The pulse peak can be used along with electrocardiographinformation to measure pulse wave transit time, which can be used tomeasure renal blood pressure. Analysis system 180 may then use the renalblood flow information to measure and monitor stress in the person.

In particular embodiments, analysis system 180 may access one or moredata streams from a renal Doppler sonograph and one or morephysiological, psychological, behavioral, or environmental sensors tomeasure and model stress in a person. The data streams may compriserenal-Doppler data of the person, physiological data of the person,psychological data of the person, behavioral of the person, orenvironmental data, respectively. The renal-Doppler data may berenal-blood-velocity data, renal-blood-flow data, renal-resistive-index,renal-vascular-resistance, or other data generated or calculated by therenal Doppler sonograph. In particular embodiments, analysis system 180may access data streams from a renal Doppler sonograph and one or moreof a heart-rate monitor, a blood-pressure monitor, a pulse oximeter, ormood sensor. Although this disclosure describes accessing particularsensors 112 and particular data streams to measure and model stress in aperson, this disclosure contemplates accessing any suitable sensors 112and any suitable data streams to measure and model stress in a person.

In particular embodiments, analysis system 180 may generate a stressmodel of a person based on data streams from a renal Doppler sonographand one or more physiological, psychological, behavioral, orenvironmental sensors. As an example and not by way of limitation, astress model may be an algorithm based on renal-Doppler data of theperson, heart-rate data of the person, blood-pressure data of theperson, pulse-oximetry data of the person, or mood data of the person.The data the stress model is based on may be baseline data collectedfrom the person during a control period. During the control period, thefollowing variables may be controlled: the user's environment; thestressors and therapies the person is exposed to; and the sampling rateof the renal Doppler sonograph and other sensors 112, and other suitablevariables. Stress may be induced by exposing a person to particularstressors, such as, for example, questionnaires, self-inducedmethodologies, media, personal interactions, or other suitablestressors. This baseline data may then be correlated with the stressindex of the person. The stress model may include a variety ofvariables, such as, for example, renal blood-velocity, renal blood-flow,heart rate, blood pressure, blood-oxygen level, stress level, or one ormore fixed variables. In particular embodiments, analysis system 180 maygenerate a model by fitting one or more data sets to a mathematicalfunction. As an example and not by way of limitation, a stress modelcould be an algorithm based on sensor measurements made by one or moresensors 112 over some control period. The stress model may include avariety of variables, including data from one or more data streams andone or more fixed variables. The following is an example algorithm thatanalysis system 180 could generate to model the stress of a person:f _(sm) =f(D _(RBV) ¹ ,D _(HR) ² ,D _(BP) ³ ,D _(SpO2) ⁴ ,D _(mood) ⁵ ,X¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model of the person,    -   (D_(RBV) ¹) is the renal blood-velocity of the person,    -   (D_(HR) ²) is the heart rate of the person,    -   (D_(BP) ³) is the blood pressure of the person,    -   (D_(SpO2) ⁴) is the blood-oxygen level of the person,    -   (D_(mood) ⁵) is the self-reported stress level of the person,        and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

In particular embodiments, the stress model may be used to calculate astress index of the person. As an example and not by way of limitation,the stress model of the person may directly calculate the stress indexof the person, such that f_(sm)=SI, where SI is the stress index of theperson. As another example and not by way of limitation, the stressindex of the person may be based on the stress model of the person, suchthat f(f_(sm))=SI. In particular embodiments, the stress index of aperson may equal the self-reported stress level of the person, such thatD_(mood) ⁵=SI. Given renal blood-velocity data, a correlation betweenself-reported stress of a person and the renal blood-velocity of theperson can be determined. Correlations between self-reported stress andother physiological parameters may also be determined, allowing thestress model to be reformulated such that D_(mood) ⁵=(D_(RBV) ¹, D_(HR)², D_(BP) ³, D_(SpO2) ⁴, X¹, . . . , X^(M)). Analysis system 180 mayalso update and refine the stress model based on new physiological,psychological, behavioral, or environmental generated by sensor array110. In particular embodiment, the stress model may be used to determinethe user's physiological and psychological state. As an example and notby way of limitation, the stress model of the person may be used tocalculate the heart rate and blood pressure of a person given the renalblood-velocity of the person. Although this disclosure describesparticular components performing particular processes to generate astress model of a person, this disclosure contemplates any suitablecomponents performing any suitable processes to generate a stress modelof a person. Moreover, although this disclosure describes particularstress models based on particular data or variables, this disclosurecontemplates any suitable stress models based on any suitable data orvariables. Furthermore, although this disclosure describes particularrelationships between the stress model of a person and the stress indexof the person, this disclosure contemplates any suitable relationshipbetween the stress model of a person and the stress index of the person.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and model stress. A typicaldiagnostic test involves generating at least two data sets, wherein thedata sets are collect from the person when he is at different stressstates. The data sets may include the person's renal-Doppler data andone or more data sets from one or more other sensors 112 in sensor array110. As an example and not by way of limitation, a first data set ofrenal-Doppler data may be collected from the person when the person isexposed to a particular stressor, and a second data set of renal-Dopplerdata may be collected from the person when the person is not exposed tothe particular stressor. As another example and not by way oflimitation, a first data set of renal-Doppler data may be collected fromthe person when he is substantially unstressed, i.e., relaxed (such as,for example, when the person reports on mood sensor 400 that he is“stressed” with an intensity of 1 or less on a 0-to-4 Likert scale),establishing the person's baseline stress level, and a second data setof renal-Doppler data may be collected from the person when he issubstantially stressed (such as, for example, when the person reports onmood sensor 400 that he is “stressed” with an intensity of 3 or more ona 0-to-4 Likert scale). Analysis system 180 may then determine how theperson's renal-Doppler changes with stress. Analysis system 180 may alsodetermine the stress factor associated with the particular stressor. Theaccuracy of the stress model may generally be increased as the number ofdata sets is increased. Therefore, multiple data sets may be generatedand analyzed to model stress in a person. Typically, the data sets willbe collected from the person when he is engaged in varying behaviors orsubjected to varying stressors.

In particular embodiments, analysis system 180 may access a data streamfrom a behavioral sensor to measure and model stress in a person,wherein the data stream comprises behavioral data of the person. Thebehavioral sensor may be any suitable user-input sensor, such as, forexample, mood sensor 400. The behavioral sensor may also be any suitabledata feed, such as, for example, an electronic calendar. Analysis system180 may then analyze the data stream containing the behavioral data ofthe person, allowing it to more accurately measure and model the stressof a person. Particular behaviors are associated with increases instress. As an example and not by way of limitation, analysis system 180could map behavioral data against stress data to determine whetherparticular activities correlate with changes in a person's stress index.

In particular embodiments, analysis system 180 may access a data streamfrom an electrocardiograph to measure and model stress in a person,wherein the data stream comprises electrocardiograph data of the person.Analysis system 180 may then analyze the data stream containing theelectrocardiograph data of the person, allowing it to more accuratelymeasure and model the stress of the person. Increases in heart rate areassociated with increases in stress. As an example and not by way oflimitation, analysis system 180 could map electrocardiograph dataagainst stress data to determine whether particular changes in the ECGwaveform correlated with changes in a person's stress index.

In particular embodiments, analysis system 180 may access a data streamfrom a glucocorticoid meter to measure and model stress in a person,wherein the data stream comprises glucocorticoid data of the person. Theglucocorticoid meter may be a biosensor for measuring glucocorticoidlevels, such as, for example, an immunoassay or chromatograph. Theglucocorticoid meter may also be any suitable user-input sensor, suchas, for example, mood sensor 400. The user-input sensor may receivesubjective stress information from the person, which may serve as abiomarker for the user's glucocorticoid level. Analysis system 180 maythen analyze the data stream containing the glucocorticoid data of theperson, allowing it to more accurately measure and model the stress ofthe person. Increases in glucocorticoid levels are associated withincreases in stress. As an example and not by way of limitation,analysis system 180 could map glucocorticoid data against stress data todetermine whether particular changes in the glucocorticoid levelscorrelate with changes in a person's stress index.

In particular embodiments, analysis system 180 may access a data streamfrom a respiration sensor to measure and model stress in a person,wherein the data stream comprises respiration data of the person.Analysis system 180 may then analyze the data stream containing therespiration data of the person, allowing it to more accurately measureand model the stress of the person. Increases in respiration rate areassociated with increases in stress. As an example and not by way oflimitation, analysis system 180 could map respiration data againststress data to determine whether particular changes in the person'srespiration rate correlated with changes in the person's stress index.

In particular embodiments, analysis system 180 may access a data streamfrom a galvanic-skin-response sensor to measure and model stress in aperson, wherein the data stream comprises galvanic-skin-response data ofthe person. Galvanic skin response is also known as electrodermalresponse, psychogalvanic reflex, or skin conductance response. Agalvanic-skin-response sensor can measure the autonomic nerve responseas a parameter of the sweat gland function by measuring the electricalresistance of the skin. As stress levels increase, changes in theelectrical resistance of the skin are detected by GSR sensors, withincrease in resistance being associated with increases in stress. As anexample and not by way of limitation, analysis system 180 could mapgalvanic-skin-response data against stress data to determine whetherparticular changes in the person's galvanic skin-response correlatedwith changes in the person's stress index.

FIG. 9 illustrates an example method 900 for creating a stress profileusing renal Doppler sonography. The method begins at step 910, whereanalysis system 180 may access one or more data streams from a pluralityof sensors 112. The sensors 112 may comprise a renal Doppler sonographand one or more of a heart-rate monitor, a pulse oximeter, or a moodsensor. The data streams may comprise renal-Doppler data of a personfrom the renal Doppler sonograph and one or more heart-rate data of theperson from the heart-rate monitor, blood-pressure data of the personfrom the blood-pressure monitor, pulse-oximetry data of the person fromthe pulse oximeter, or mood data of the person from the mood sensor. Atstep 920, analysis system 180 may generate a stress model of the personbased on the data streams. Although this disclosure describes andillustrates particular steps of the method of FIG. 9 as occurring in aparticular order, this disclosure contemplates any suitable steps of themethod of FIG. 9 occurring in any suitable order. Moreover, althoughthis disclosure describes and illustrates particular components carryingout particular steps of the method of FIG. 9, this disclosurecontemplates any suitable combination of any suitable componentscarrying out any suitable steps of the method of FIG. 9.

Continuous Monitoring of Stress Using a Stress Profile Created by RenalDoppler Sonography

As discussed previously, stress may be measured using a variety ofmethods. However measuring and monitoring stress using these methods maybe difficult because different persons may respond to stressdifferently. Furthermore, a person may undergo a variety ofphysiological and psychological changes due to a variety of disparatereasons, including stress. Consequently, it may be difficult to make aprecise determination of stress based on a sensor reading alone. Astress profile of a person that accounts for a variety of physiological,psychological, behavioral, and environmental factors may be needed toaccurately measure stress levels in a person.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more physiological, psychological, behavioral,or environmental sensors to measure and monitor stress in a person. Thedata streams may comprise physiological data of the person,psychological data of the person, behavioral of the person, orenvironmental data, respectively. In particular embodiments, analysissystem 180 may access data streams from one or more of a heart-ratemonitor, a blood-pressure monitor, a pulse oximeter, a mood sensor, oran accelerometer. Although this disclosure describes accessingparticular sensors 112 and particular data streams to measure andmonitor stress in a person, this disclosure contemplates accessing anysuitable sensors 112 and any suitable data streams to measure andmonitor stress in a person.

In particular embodiments, analysis system 180 may access a stressmodel. As an example and not by way of limitation, a stress model may bean algorithm based on renal-Doppler data, heart-rate data,blood-pressure data, pulse-oximetry data, or mood data. As an exampleand not by way of limitation, a stress model could be an algorithm basedon sensor measurements made by one or more sensors 112 over some controlperiod. The stress model may include a variety of variables, includingdata from one or more data streams and one or more fixed variables. Thefollowing is an example algorithm that analysis system 180 could accessthat models the stress of a person:f _(sm) =f(D _(HR) ¹ ,D _(BP) ² ,D _(SpO2) ³ ,D _(mood) ⁴ ,D _(acc) ⁵ ,X¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(HR) ¹) is the heart rate of the person,    -   (D_(BP) ²) is the blood pressure of the person,    -   (D_(SpO2) ³) is the blood-oxygen level of the person,    -   (D_(mood) ⁴) is the self-reported stress level of the person,    -   (D_(acc) ⁵) is the activity (acceleration) of the person, and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

The stress model may be a stress model based on baseline data from oneor more persons. In particular embodiments, the stress model may be astress model of a person who is the subject of sensor array 110. That isto say that analysis system 180 may currently be measuring andmonitoring stress in a first person and the stress model may be based onbaseline data of the first person. This stress model of the person maybe based on baseline data collected from the person during a controlperiod. In particular embodiments, the stress model may be a stressmodel of one or more persons who are not currently the subject of sensorarray 110. That is to say that analysis system 180 may currently bemeasuring and monitoring stress in a first person and the stress modelmay be based on baseline data of one or more second persons. This stressmodel of the one or more second persons may be based on baseline datacollected from the second persons during a control period. Generatingand using a stress model of one or more second persons may allow stressto be accurately measured in the first person without having to generatea personalized stress profile for the first person, which may beexpensive and time-consuming. The first person and the one or moresecond persons may be in the same subset of patients, patient group, orpatient cohort. As an example and not by way of limitation, the firstperson and the second persons may be in the same age group, ethnicgroup, racial group, patient population, or another suitable category ofpersons. As another example and not by way of limitation, the patientsmay be part of the same medically plausible subset of the patientpopulation for a common disease or condition. Medically plausiblesubsets generally include groups of patients with special requirementsor characteristics that distinguish them from the larger diseasegrouping. A medically plausible subset may be a patient subpopulationthat demonstrates unique pharmacological or pharmacodynamiccharacteristics. The term patient, as used herein, may refer to anyperson and is not limited to a person who is receiving medicalattention, care, or treatment. Although this disclosure describes stressmodels based on particular persons or groups of persons, this disclosurecontemplates stress models based on any suitable persons or groups ofpersons.

In particular embodiments, analysis system 180 may analyze the datastreams with respect to the stress model. Analysis system 180 may useany suitable process, calculation, or technique to analyze the datastreams with respect to the stress model. As an example and not by wayof limitation, analysis system 180 may analyze the stress model toidentify independent variables that correspond to particular datastreams. Analysis system 180 may then analyze the data streams andidentify data points or data ranges from the data streams that may beused as inputs into the stress model. Although this disclosure describesparticular components performing particular processes to analyze thedata streams with respect to the stress model, this disclosurecontemplates any suitable components performing any suitable processesto analyze the data streams with respect to the stress model.

In particular embodiments, analysis system 180 may determine the currentstress index of a person. The stress model may be used to calculate astress index of the person. As an example and not by way of limitation,the stress model may directly calculate the stress index of the person,such that f_(sm)=SI, where SI is the stress index of the person. Asanother example and not by way of limitation, the stress index of theperson may be based on the stress model, such that f(f_(sm))=SI.Analysis system 180 may calculate the stress index of the person basedon the data from one or more of the data streams. As an example and notby way of limitation, analysis system 180 may input data points or dataranges from the data streams into the stress model as independentvariables. Analysis system 180 may then calculate the stress index ofthe person by solving the stress model. Although this disclosuredescribes particular components performing particular processes todetermine the current stress index of a person, this disclosurecontemplates any suitable components performing any suitable processesto determine the current stress index of a person. Moreover, althoughthis disclosure describes particular relationships between the stressmodel of a person and the stress index of the person, this disclosurecontemplates any suitable relationship between the stress model of aperson and the stress index of the person.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stress. A typicaldiagnostic test involves generating at least two data sets, wherein thedata sets are collect from the person when he is at different stressstates. The data sets may include one or more data sets from one or moresensors 112 in sensor array 110. As an example and not by way oflimitation, a first data set may be collected from the person when theperson is exposed to a particular stressor, and a second data set may becollected from the person when the person is not exposed to theparticular stressor. As another example and not by way of limitation, afirst data set may be collected from the person when he is substantiallyunstressed, i.e., relaxed (such as, for example, when the person reportson mood sensor 400 that he is “stressed” with an intensity of 1 or lesson a 0-to-4 Likert scale), establishing the person's baseline stresslevel, and a second data set may be collected from the person when he issubstantially stressed (such as, for example, when the person reports onmood sensor 400 that he is “stressed” with an intensity of 3 or more ona 0-to-4 Likert scale). Analysis system 180 may then determine how theperson's physiological or psychological states change with stress.Analysis system 180 may also determine the stress factor associated withthe particular stressor. The accuracy of determining stress in a personmay generally be increased as the number of data sets is increased.Therefore, multiple data sets may be generated and analyzed to determinestress in a person. Typically, the data sets will be collected from theperson when he is engaged in varying behaviors or subjected to varyingstressors.

In particular embodiments, analysis system 180 may access the stressindex history of a person to determine if the stress index of the personhas changed over time. As an example and not by way of limitation,analysis system 180 may access a stress index of the person that waspreviously determined. Analysis system 180 may then analyze the priorstress index and compare it to one or more subsequently determinedstress indexes to determine whether the stress index has changed withrespect to the previously determined stress index. Analysis system 180may determine whether there are any trends in the person's stress indexover time or with respect to one or more physiological, psychological,behavioral, or environmental data streams. For example, analysis system180 could map the person's blood pressure over time against the person'sstress index over time to determine whether there are any correlatingtrends between the two data sets (e.g., the user's blood pressure andstress are both trending up with time). Although this disclosuredescribes particular components performing particular processes todetermine if the stress index of a person has changed over time, thisdisclosure contemplates any suitable components performing any suitableprocesses to determine if the stress index of a person has changed overtime.

In particular embodiments, analysis system 180 may access a data streamfrom a behavioral sensor to measure and monitor stress in a person,wherein the data stream comprises behavioral data of the person. Thebehavioral sensor may be any suitable user-input sensor, such as, forexample, mood sensor 400. The behavioral sensor may also be any suitabledata feed, such as, for example, an electronic calendar. Analysis system180 may then analyze the data stream containing the behavioral data ofthe person, allowing it to more accurately measure and monitor thestress of a person. Particular behaviors are associated with increasesin stress. As an example and not by way of limitation, analysis system180 could map behavioral data against physiological data to determinewhether particular physiological changes are caused by particularactivities or by stress.

In particular embodiments, analysis system 180 may access a data streamfrom an electrocardiograph to measure and monitor stress in a person,wherein the data stream comprises electrocardiograph data of the person.Analysis system 180 may then analyze the data stream containing theelectrocardiograph data of the person, allowing it to more accuratelymeasure and monitor the stress of the person. Increases in heart rateare associated with increases in stress. As an example and not by way oflimitation, analysis system 180 could map electrocardiograph dataagainst other physiological data to determine whether particularphysiological changes are caused by changes in the ECG waveform or bystress.

In particular embodiments, analysis system 180 may access a data streamfrom a glucocorticoid meter to measure and monitor stress in a person,wherein the data stream comprises glucocorticoid data of the person. Theglucocorticoid meter may be a biosensor for measuring glucocorticoidlevels, such as, for example, an immunoassay or chromatograph. Theglucocorticoid meter may also be any suitable user-input sensor, suchas, for example, mood sensor 400. The user-input sensor may receivesubjective stress information from the person, which may serve as abiomarker for the user's glucocorticoid level. Analysis system 180 maythen analyze the data stream containing the glucocorticoid data of theperson, allowing it to more accurately measure and monitor the stress ofthe person. Increases in glucocorticoid levels are associated withincreases in stress. As an example and not by way of limitation,analysis system 180 could map glucocorticoid data against otherphysiological data to determine whether particular physiological changesare caused by changes in glucocorticoid levels or by stress.

In particular embodiments, analysis system 180 may access a data streamfrom an electromyograph to measure and monitor stress in a person,wherein the data stream comprises electromyograph data of the person.Analysis system 180 may then analyze the data stream containing theelectromyograph data of the person, allowing it to more accuratelymeasure and monitor the stress of the person. As an example and not byway of limitation, analysis system 180 could map electromyograph dataagainst other physiological data to determine whether particularphysiological changes are caused by particular muscle activity or bystress.

In particular embodiments, analysis system 180 may access a data streamfrom a respiration sensor to measure and model stress in a person,wherein the data stream comprises respiration data of the person.Analysis system 180 may then analyze the data stream containing therespiration data of the person, allowing it to more accurately measureand model the stress of the person. Increases in respiration rate areassociated with increases in stress. As an example and not by way oflimitation, analysis system 180 could map respiration data against otherphysiological data to determine whether particular physiological changesare caused by changes in the person's respiration rate.

In particular embodiments, analysis system 180 may access a data streamfrom a galvanic-skin-response sensor to measure and model stress in aperson, wherein the data stream comprises galvanic-skin-response data ofthe person. Galvanic skin response is also known as electrodermalresponse, psychogalvanic reflex, or skin conductance response. Agalvanic-skin-response sensor can measure the autonomic nerve responseas a parameter of the sweat gland function by measuring the electricalresistance of the skin. As stress levels increase, changes in theelectrical resistance of the skin are detected by GSR sensors, withincrease in resistance being associated with increases in stress. As anexample and not by way of limitation, analysis system 180 could mapgalvanic-skin-response data against other physiological data todetermine whether particular physiological changes are caused by changesin the person's galvanic skin-response.

FIG. 10 illustrates an example method 1000 for monitoring stress using astress profile created by renal Doppler sonography. The method begins atstep 1010, where analysis system 180 may access one or more data streamsfrom a plurality of sensors 112. The sensors 112 may comprise one ormore of a heart-rate monitor, a blood-pressure monitor, a pulseoximeter, a mood sensor, or an accelerometer. The data streams maycomprise one or more of heart-rate data of a person from the heart-ratemonitor, blood-pressure data of the person from the blood-pressuremonitor, pulse oximetry data of the person from the pulse oximeter, mooddata of the person from the mood sensor, or accelerometer data of theperson from the accelerometer. At step 1020, analysis system 180 mayaccess a stress model. The stress model may comprise baselinerenal-Doppler data and two or more of baseline heart-rate data, baselineblood-pressure data, baseline pulse oximetry data, or baseline mooddata. At step 1030, analysis system 180 may analyze the data streamswith respect to the stress model. At step 1040, analysis system 180 maydetermine based on the analysis a current stress index of the person.Although this disclosure describes and illustrates particular steps ofthe method of FIG. 10 as occurring in a particular order, thisdisclosure contemplates any suitable steps of the method of FIG. 10occurring in any suitable order. Moreover, although this disclosuredescribes and illustrates particular components carrying out particularsteps of the method of FIG. 10, this disclosure contemplates anysuitable combination of any suitable components carrying out anysuitable steps of the method of FIG. 10.

Continuous Monitoring of Stress Using Self-Reported Psychological orBehavioral Data

One problem in measuring and monitoring stress accurately is determiningwhether any changes in measured parameters are taking place due tonon-stress related activity from the user that confound the analysis(i.e., confounding factors). Various physiological sensors may be usedin an attempt to measure stress, such as, for example, heart-ratemonitors, blood-pressure monitors, pulse oximeters, or respirationsensors. However, physiological changes that correlate with stress mayactually be caused by non-stress events. For example, an increase inheart rate is associated with an increase in stress, but it is alsoassociated with exercise, which may in fact cause a decrease in stress.Similarly, physiological or psychological data indicating stress may bedue to confounding factors and may in fact be contradicted by apatient's self-reported non-stressed state. By using a mood sensor orbehavioral sensor, such as mood sensor 400, a patient may inputpsychological data (e.g., happy, anxious, sad, stressed) or behavioraldata (e.g., running, driving, fighting, working). By contextualizingphysiological sensor data with this psychological or behavioral data,analysis system 180 may be able to eliminate changes in physiologicaldata caused by non-stress related events and thereby more accuratelymeasure and monitor stress in a person.

In particular embodiments, analysis system 180 may measure and monitorstress by analyzing one or more data streams from one or more moodsensors, such as, for example, mood sensor 400. A user may inputpsychological (i.e., mood) information into mood sensor 400. A moodsensor may receive information regarding a user's subjective experienceof stress. A user's subjective experience of stress may act as abiomarker for various physiological states, including, for example, theuser's glucocorticoid and catecholamine levels. The user may inputstress, for example, on mood input widget 430. The user could then inputan intensity of the stress, for example, on mood intensity widget 440.After receiving the user's mood information, the mood sensor may thentransmit one or more data streams comprising the user's mood data toanalysis system 180. As an example and not by way of limitation, a usermay report mood information by inputting that he is “stressed” with anintensity of 2 on a 0-to-4 Likert scale using mood input widget 430 andmood intensity widget 440. A mood sensor may also receive informationregarding a user's general psychological state, which may correlate withstress. As an example and not by way of limitation, a user may reportmood information by inputting that he is “angry” with an intensity of 3on a 0-to-4 Likert scale. Analysis system 180 may then analyze this moodand mood intensity data by inputting it into a stress model thatcorrelates psychological states with stress to calculate the user'sstress index. Analysis system 180 may continuously monitor a data streamcontaining psychological data, thereby allowing it to accurately measureand monitor a user's stress and stress-related health states. Althoughthis disclosure describes measuring and monitoring stress usingparticular types of mood sensors, this disclosure contemplates measuringand monitoring stress using any suitable mood sensors.

In particular embodiments, analysis system 180 may measure and monitorstress by analyzing one or more data streams from one or more behavioralsensors, such as, for example, mood sensor 400. A user's behaviorinformation may be correlated with other stress-related data. A user mayinput behavioral (i.e., activity) information into mood sensor 400. Theuser may input a behavior, for example, on activity input widget 450.After receiving the user's behavioral information, the behavioral sensormay then transmit one or more data streams comprising the user'sbehavioral data to analysis system 180. As an example and not by way oflimitation, a user may report behavioral data by inputting that he is“driving” using activity input widget 450. Analysis system 180 may thenanalyze this behavioral data by inputting it into a stress model thatcorrelates behavioral states with stress to calculate the user's stressindex. Alternatively, analysis system 180 may calculate the user'sstress index using other factors and then correlate a user's stress withspecific behaviors by the user. Similarly, analysis system 180 maycorrelate a user's lack of stress (i.e., relaxation) with specificbehavior or activities by the user. Analysis system 180 may continuouslymonitor a data stream containing behavioral data, thereby allowing it toaccurately measure and monitor a user's stress and stress-related healthstates. Although this disclosure describes diagnosing and monitoringstress using particular types of behavioral sensors, this disclosurecontemplates diagnosing and monitoring stress using any suitable typesof behavioral sensors. As an example and not by way of limitation, anelectronic calendar may be a behavioral sensor, wherein calendar entriesmay describe a person's behavior at particular times. Analysis system180 may then access a data stream from the electronic calendar with thisbehavioral data.

In particular embodiments, analysis system 180 may access apsychological or behavioral data stream and one or more physiologicaldata streams to measure and monitor stress in a person. The data streamsmay comprise psychological data of the person, behavioral of the person,or physiological data of the person, respectively. In particularembodiments, analysis system 180 may access data streams from a moodsensor or behavioral sensors and one or more of a heart-rate monitor, ablood-pressure monitor, a pulse oximeter, or an accelerometer. Althoughthis disclosure describes accessing particular sensors 112 andparticular data streams to measure and monitor stress in a person, thisdisclosure contemplates accessing any suitable sensors 112 and anysuitable data streams to measure and monitor stress in a person.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stress in aperson. A typical diagnostic test involves generating at least two datasets, wherein the data sets are collect from the person when he is atdifferent psychological or behavioral states. The data sets may includeone or more data sets from one or more sensors 112 in sensor array 110.As an example and not by way of limitation, a first data set may becollected from the person when the person is in a first mood (e.g.,stressed), and a second data set may be collect from the person when theperson is in a second mood (e.g., unstressed). As another example andnot by way of limitation, a first data set may be collected from theperson when the person is engaged in a first activity (e.g., sleeping),and a second data set may be collected from the person when the personis engaged in a second activity (e.g., exercising). As yet anotherexample and not by way of limitation, a first data set may be collectedfrom the person when the person is exposed to a particular stressor(e.g., being asked to solve a difficult analytical problem), and asecond data set may be collected from the person when the person is notexposed to the particular stressor. Analysis system 180 may then use thepsychological or behavioral data to deconfound the physiological data todetermine whether changes in the physiological state of a person arecaused by stress or by a particular psychological or behavioral state.The accuracy of determining stress in a person may generally beincreased as the number of data sets is increased. Therefore, multipledata sets may be generated and analyzed to determine stress in a person.Although this disclosure describes accessing particular data sets tomeasure and monitor stress in a person, this disclosure contemplatesaccessing any suitable data sets to measure and monitor stress in aperson.

In particular embodiments, analysis system 180 may access a stress modelof a person. As an example and not by way of limitation, a stress modelmay be an algorithm based on renal-blood-velocity data and mood orbehavioral data and heart-rate data, blood-pressure data, pulse-oximetrydata, or accelerometer data. As an example and not by way of limitation,a stress model could be an algorithm based on sensor measurements madeby one or more sensors 112 over some control period. The stress modelmay include a variety of variables, including data from one or more datastreams and one or more fixed variables. The following is an examplealgorithm that analysis system 180 could access that models the stressof a person:f _(sm) =f(D _(mood) ¹ ,D _(beh) ² ,D _(HR) ³ ,D _(BP) ⁴ ,D _(SpO2) ⁵ ,D_(acc) ⁶ ,X ¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(mood) ¹) is the psychological state (mood) of the person,    -   (D_(beh) ²) is the behavioral state (activity) of the person,    -   (D_(HR) ³) is the heart rate of the person,    -   (D_(BP) ⁴) is the blood pressure of the person,    -   (D_(SpO2) ⁵) is the blood-oxygen level of the person,    -   (D_(acc) ⁶) is the physical activity (acceleration) of the        person, and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

In particular embodiments, analysis system 180 may analyze data setsfrom the psychological or behavioral data streams and the physiologicaldata streams with respect to each other. Analysis system 180 may use anysuitable process, calculation, or technique to analyze the data streamswith respect to each other. As an example and not by way of limitation,analysis system 180 may compare the first data set and a second data toidentify any changes in the physiological state of the person and toidentify any corresponding changes in psychological or behavioral state.As another example and not by way of limitation, analysis system 180 mayanalyze the data streams and identify data points or data ranges fromthe data streams that may be used as inputs into a stress model. Inparticular embodiments, analysis system 180 may contextualize thephysiological data with the psychological or behavioral data, such as,for example, by mapping the data with respect to each other. As anexample and not by way of limitation, analysis system 180 maycontextualize heart-rate data, blood-pressure data, pulse-oximetry data,and accelerometer data of the person with the mood data of the person,allowing analysis system 180 to identify correlations between changes inthe physiological data and the mood data. Although this disclosuredescribes particular components performing particular processes toanalyze the data streams with respect to each other, this disclosurecontemplates any suitable components performing any suitable processesto analyze the data streams with respect to each other.

In particular embodiments, analysis system 180 may determine the currentstress index of a person based on the analysis of a plurality of datasets from the psychological or behavioral data streams and thephysiological data streams with respect to each other. The stress indexmay be determined both from the psychological or behavior state of theperson and the physiological state of the person. Various psychologicalstates may correlate with stress, such as, for example, stress, anger,anxiety, or depression. Other psychological states may correlate with alack of stress, such as, for example, happiness or relaxation. Variousbehavioral states may correlate with stress, such as, for example,working, arguing, or driving. Other behavioral states may correlate witha lack of stress, such as, for example, socializing, relaxing, orexercising. Various physiological states may correlate with stress, suchas, for example, increased heart rate, increased blood pressure, ordecreased blood oxygen. As an example and not by way of limitation,analysis system 180 may examine the data streams and identifypsychological, behavioral, or physiological states that correlate withstress or a lack of stress. Analysis system 180 may analyze one data setto determine the baseline stress of the person and then analyze anotherdata set to determine the change in the person's psychological,behavioral, or physiological states to determine a current stress indexof the person. Analysis system 180 may determine the current stressindex of the person by determining the magnitude that each of thepsychological, behavioral, or physiological states correlates withstress or lack of stress. As an example and not by way of limitation, alow blood pressure may correlate with a low stress index while a highblood pressure may correlate with a high stress index. As anotherexample and not by way of limitation, a self-reported psychologicalstate of “happy” with an intensity of 3 on a 0-to-4 Likert scale maycorrelate with a low stress index while a self-reported psychologicalstate of “happy” with an intensity of 0 on a 0-to-4 Likert scale maycorrelate with a high stress index. As yet another example, a behavioralstate of “relaxing” may correlate with a low stress index while abehavioral state of “arguing” may correlate with a high stress index.Although this disclosure describes particular components performingparticular processes to determine the current stress index of a person,this disclosure contemplates any suitable components performing anysuitable processes to determine the current stress index of a person.Moreover, although this disclosure describes analyzing particular datastreams for particular correlations to determine the current stressindex of a person, this disclosure contemplates analyzing any suitabledata streams for any suitable correlations to determine the currentstress index of a person.

In particular embodiments, analysis system 180 may use a stress model ofa person to determine the current stress index of the person based onthe analysis of data sets from the psychological or behavioral datastreams and the physiological data streams with respect to each other.As an example and not by way of limitation, the stress model maydirectly calculate the stress index of the person, such that f_(sm)=SI,where SI is the stress index of the person. As another example and notby way of limitation, the stress index of the person may be based on thestress model, such that f(f_(sm))=SI. Analysis system 180 may calculatethe stress index of the person based on the data from one or more of thepsychological or behavioral data streams and the physiological datastreams. As an example and not by way of limitation, analysis system 180may input data points or data ranges from the psychological orbehavioral data streams and the physiological data streams into thestress model as independent variables. Analysis system 180 may thencalculate the stress index of the person by solving the stress model.Although this disclosure describes particular components performingparticular processes to determine the current stress index of a person,this disclosure contemplates any suitable components performing anysuitable processes to determine the current stress index of a person.Moreover, although this disclosure describes particular relationshipsbetween the stress model of a person and the stress index of the person,this disclosure contemplates any suitable relationship between thestress model of a person and the stress index of the person.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more additional sensors 112 to measure andmonitor stress in a person. As described previously, analysis system 180may access, for example, an electrocardiograph, a glucocorticoid meter,an electromyograph, a respiration sensor, a galvanic-skin-responsesensor, or another suitable sensor 112. Analysis system 180 may thenanalyze these additional data streams, allowing it to more accuratelymeasure and monitor the stress of the person, such as, for example, bydeconfounding physiological data caused by non-stress related events.

FIG. 11 illustrates an example method 1100 for monitoring stress usingpsychological or behavioral data. The method begins at step 1110, whereanalysis system 180 accesses one or more data streams from a pluralityof sensors 112. The sensors 112 may comprise a mood (psychological)sensor and one or more of a heart-rate monitor, a blood-pressuremonitor, a pulse oximeter, or an accelerometer. The data streams maycomprise mood (psychological) data of a person from the mood sensor andone or more of heart-rate data of the person from the heart-ratemonitor, blood-pressure data of the person from the blood-pressuremonitor, pulse oximetry data of the person from the pulse oximeter, oraccelerometer data of the person from the accelerometer. A first dataset from the data streams may be collected from the person at a firsttime and the person may be substantially stressed at the first time. Asecond data set from the data streams may be collected from the personat a second time and the person may be substantially unstressed at thesecond time. At step 1120, analysis system 180 may analyze the firstdata set and the second data set with respect to each other. At step1130, analysis system 180 may determine a current stress index of theperson based on the analysis of the first data set and the second dataset with respect to each other. Although this disclosure describes andillustrates particular steps of the method of FIG. 11 as occurring in aparticular order, this disclosure contemplates any suitable steps of themethod of FIG. 11 occurring in any suitable order. Moreover, althoughthis disclosure describes and illustrates particular components carryingout particular steps of the method of FIG. 11, this disclosurecontemplates any suitable combination of any suitable componentscarrying out any suitable steps of the method of FIG. 11.

Continuous Monitoring of Stress Using Accelerometer Data

As discussed previously, one problem in measuring and monitoring stressaccurately is determining whether any changes in measured parameters aretaking place due to non-stress related activity (such as, for example,by the user) that confound the analysis. Various physiological sensorsmay be used in an attempt to measure stress, such as, for example,heart-rate monitors, blood-pressure monitors, pulse oximeters, orrespiration sensors. However, physiological changes that correlate withstress may actually be caused by non-stress events. For example,increases in heart rate, blood pressure, and respiration are associatedwith increases in stress, but they are also associated with physicalmovement, which may be caused by a non-stress event (such as, forexample, exercise). Physical exertion changes heart rate, bloodpressure, heart rate variability, respiratory rate, oxygen saturation,sweat and galvanic skin response, as well as blood glucose level. All ofthese can be used as crucial markers for accurately estimating stress.For example, when using heart-rate variability to measure stress, theresults may be confounded if physical movement and exertion is not takeninto account during the stress measurement. Furthermore, many sensorsprovide erroneous data when accelerated, for example, because thephysical connection between the sensor and the subject moves, causingthe sensor to generate an inaccurate or false reading. By using anaccelerometer (or another suitable movement sensor, such as, forexample, a kinesthetic sensor), analysis system 180 may monitor thephysical movement and exertion of a person. By contextualizingphysiological sensor data with accelerometer data, analysis system 180may be able to eliminate changes in physiological data or erroneoussensor measurements caused by physical movement and thereby moreaccurately measure and monitor stress in a person.

In particular embodiments, analysis system 180 may measure and monitorstress by analyzing one or more data streams from one or more physicalmotion sensors, such as, for example, an accelerometer, a kinestheticsensor, an actigraph, a motion sensor, or another suitable physicalmotion sensor. A physical motion sensor may measure a person's speed,acceleration, exertion, movement, or exertion. After measuring theperson's physical motion, the physical motion sensor may then transmitone or more data streams comprising the user's physical motion data toanalysis system 180. Analysis system 180 may then analyze this physicalmotion by inputting it into a stress model that correlates physicalmotion with stress to calculate the person's stress index. Analysissystem 180 may continuously monitor a data stream containing physicalmotion data of a person, thereby allowing it to accurately measure andmonitor the person's stress and stress-related health states. Althoughthis disclosure describes measuring and monitoring stress usingparticular types of physical motion sensors, this disclosurecontemplates measuring and monitoring stress using any suitable physicalmotion sensors.

In particular embodiments, analysis system 180 may access one or moredata streams from an accelerometer and one or more of other sensors 112to measure and monitor stress in a person. The data streams may comprisepsychological data of the person, behavioral data of the person, orphysiological data of the person. In particular embodiments, analysissystem 180 may access data streams from an accelerometer and one or moreof a heart-rate monitor, a blood-pressure monitor, a pulse oximeter, ora mood sensor. Although this disclosure describes accessing particularsensors 112 and particular data streams to measure and monitor stress ina person, this disclosure contemplates accessing any suitable sensors112 and any suitable data streams to measure and monitor stress in aperson.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stress in aperson. A typical diagnostic test involves generating at least two datasets, wherein the data sets are collect from the person when he isengaged in different levels of physical activity. The data sets mayinclude one or more data sets from one or more sensors 112 in sensorarray 110. As an example and not by way of limitation, a first data setmay be collected from the person when the person is engaged in a firstactivity (e.g., walking), and a second data set may be collected fromthe person when the person is engaged in a second activity (e.g.,running). As another example and not by way of limitation, a first dataset may be collected from the person when the person is substantiallyresting, and a second data set may be collected from the person when theperson is engage in more than minimal activity. Analysis system 180 maythen use the accelerometer data to deconfound the data from othersensors 112 to determine whether measured changes in the physiologicalstate of a person are caused by stress or by the physical motion of theperson. The accuracy of determining stress in a person may generally beincreased as the number of data sets is increased. Therefore, multipledata sets may be generated and analyzed to determine stress in a person.Although this disclosure describes accessing particular data sets tomeasure and monitor stress in a person, this disclosure contemplatesaccessing any suitable data sets to measure and monitor stress in aperson.

In particular embodiments, analysis system 180 may access a stress modelof a person. As an example and not by way of limitation, a stress modelmay be an algorithm based on renal-Doppler data and accelerometer dataand one or more of heart-rate data, blood-pressure data, pulse-oximetrydata, or mood data. As an example and not by way of limitation, a stressmodel could be an algorithm based on sensor measurements made by one ormore sensors 112 over some control period. The stress model may includea variety of variables, including data from one or more data streams andone or more fixed variables. The following is an example algorithm thatanalysis system 180 could access that models the stress of a person:f _(sm) =f(D _(acc) ¹ ,D _(HR) ² ,D _(BP) ³ ,D _(SpO2) ⁴ ,D _(mood) ⁵ ,X¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(acc) ¹) is the physical activity (acceleration) of the        person,    -   (D_(HR) ²) is the heart rate of the person,    -   (D_(BP) ³) is the blood pressure of the person,    -   (D_(SpO2) ⁴) is the blood-oxygen level of the person,    -   (D_(mood) ⁵) is the psychological state (mood) of the person,        and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

In particular embodiments, analysis system 180 may analyze data setsfrom the accelerometer data stream and one or more other data streamswith respect to each other. Analysis system 180 may use any suitableprocess, calculation, or technique to analyze the data streams withrespect to each other. As an example and not by way of limitation,analysis system 180 may compare the first data set and a second data toidentify any changes in the acceleration of the person and to identifyany corresponding changes in physiological state. As another example andnot by way of limitation, analysis system 180 may analyze the datastreams and identify data points or data ranges from the data streamsthat may be used as inputs into a stress model. In particularembodiments, analysis system 180 may contextualize the acceleration datawith other data, such as, for example, by mapping the data with respectto each other. As an example and not by way of limitation, analysissystem 180 may contextualize accelerometer data of the person withheart-rate data, blood-pressure data, pulse-oximetry data, and mood dataof the person, allowing analysis system 180 to identify correlationsbetween changes in the acceleration data and the other data. Althoughthis disclosure describes particular components performing particularprocesses to analyze the data streams with respect to the each other,this disclosure contemplates any suitable components performing anysuitable processes to analyze the data streams with respect to the eachother.

In particular embodiments, analysis system 180 may determine the currentstress index of a person based on the analysis of a plurality of datasets from the accelerometer data stream and one or more other datastreams with respect to each other. The stress index may be determinedboth from the acceleration of the person and the physiological state ofthe person. As discussed previously, various physiological states maycorrelate with stress, such as, for example, increased heart rate,increased blood pressure, or decreased blood oxygen. However, these samephysiological states may also correlate with increased physical motion(e.g., acceleration). As an example and not by way of limitation,analysis system 180 may examine the data streams and identifyphysiological states that correlate with stress or a lack of stress andidentify whether the measured physiological states correlate withacceleration of the person. Analysis system 180 may analyze one data setto determine the baseline stress of the person and then analyze anotherdata set to determine the change in the person's physiological states todetermine a current stress index of the person. Analysis system 180 maydetermine the current stress index of the person by determining themagnitude that each of the physiological states correlates with stressor lack of stress. As an example and not by way of limitation, a lowheart rate and low acceleration may correlate with a low stress indexwhile a high heart rate and low acceleration may correlate with a highstress index. Although this disclosure describes particular componentsperforming particular processes to determine the current stress index ofa person, this disclosure contemplates any suitable componentsperforming any suitable processes to determine the current stress indexof a person. Moreover, although this disclosure describes analyzingparticular data streams for particular correlations to determine thecurrent stress index of a person, this disclosure contemplates analyzingany suitable data streams for any suitable correlations to determine thecurrent stress index of a person.

In particular embodiments, analysis system 180 may use a stress model ofa person to determine the current stress index of the person based onthe analysis of data sets from the accelerometer data stream and one ormore other data streams with respect to each other. As an example andnot by way of limitation, the stress model may directly calculate thestress index of the person, such that f_(sm)=SI, where SI is the stressindex of the person. As another example and not by way of limitation,the stress index of the person may be based on the stress model, suchthat f(f_(sm))=SI. Analysis system 180 may calculate the stress index ofthe person based on the data from the accelerometer data stream and theother data streams. As an example and not by way of limitation, analysissystem 180 may input data points or data ranges from the accelerometerdata stream and the other data streams into the stress model asindependent variables. Analysis system 180 may then calculate the stressindex of the person by solving the stress model. Although thisdisclosure describes particular components performing particularprocesses to determine the current stress index of a person, thisdisclosure contemplates any suitable components performing any suitableprocesses to determine the current stress index of a person. Moreover,although this disclosure describes particular relationships between thestress model of a person and the stress index of the person, thisdisclosure contemplates any suitable relationship between the stressmodel of a person and the stress index of the person.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more additional sensors 112 to measure andmonitor stress in a person. As described previously, analysis system 180may access, for example, a behavioral sensor, an electrocardiograph, aglucocorticoid meter, an electromyograph, a respiration sensor, agalvanic-skin-response sensor, or another suitable sensor 112. Analysissystem 180 may then analyze these additional data streams, allowing itto more accurately measure and monitor the stress of the person, suchas, for example, by deconfounding physiological data caused bynon-stress related events.

FIG. 12 illustrates an example method 1200 for monitoring stress usingaccelerometer data. The method begins at step 1210, where analysissystem 180 accesses one or more data streams from a plurality of sensors112. The sensors 112 may comprise an accelerometer and one or more of aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, or amood sensor. The data streams may comprise accelerometer data of aperson from the accelerometer and one or more of heart-rate data of theperson from the heart rate monitor, blood-pressure data of the personfrom the blood-pressure monitor, pulse-oximetry data of the person fromthe pulse oximeter, and mood data of the person from the mood sensor. Afirst data set from the data streams may be collected from the person ata first time and the person may be engaged in a first activity at thefirst time. A second data set from the data streams may be collectedfrom the person at a second time and the person may be engaged in asecond activity at the second time. At step 1220, analysis system 180may analyze the first data set and the second data set with respect toeach other. At step 1230, analysis system 180 may determine a currentstress index of the person based on the analysis of the first data setand the second data set with respect to each other. Although thisdisclosure describes and illustrates particular steps of the method ofFIG. 12 as occurring in a particular order, this disclosure contemplatesany suitable steps of the method of FIG. 12 occurring in any suitableorder. Moreover, although this disclosure describes and illustratesparticular components carrying out particular steps of the method ofFIG. 12, this disclosure contemplates any suitable combination of anysuitable components carrying out any suitable steps of the method ofFIG. 12.

Continuous Monitoring of Stress Using Environmental Data

Another problem in measuring and monitoring stress accurately isdetermining whether any changes in measured parameters are caused byenvironmental (i.e., exogenous) factors. Various physiological sensorsmay be used in an attempt to measure stress, such as, for example,heart-rate monitors, blood-pressure monitors, pulse oximeters, orrespiration sensors. However, because stress is often caused byenvironmental factors, determining the causes of stress may beimpossible by monitoring physiological sensors alone. Variousenvironmental sensors may be used in an attempt to monitor stress, suchas, for example, barometers, location sensors, traffic sensors, or datafeeds. For example, increases in heart rate, blood pressure, andrespiration in a person are associated with increases in stress in theperson. But measuring merely these physiological may tell nothing aboutthe cause of stress in the person. These physiological responses may becaused by environmental stressors, such as, for example, changingweather, changing the person's location, encountering traffic, orreceiving news from a data feed. Most current methods for measuringstress only consider physiological data associated with the subject,thus removing the analysis from its context. Consequently, it may bedifficult to establish the causes of stress without an understanding ofenvironmental factors that may act as stressors. By contextualizingphysiological sensor data with this environmental data, analysis system180 may be able to identify changes in physiological data caused byexogenous events and thereby more accurately measure and monitor stressin a person, and more accurately identify the environmental causes ofstress (i.e., stressors) for the person.

In particular embodiments, analysis system 180 may measure and monitorstress by analyzing one or more data streams from one or moreenvironmental sensors. The environmental sensors may include, forexample, a barometer, a weather sensor, a pollen counter, a locationsensor, a seismometer, an altimeter, a hydrometer, a decibel meter, alight meter, a thermometer, a wind sensor, a traffic sensor, anothersuitable environmental sensor, or two or more such sensors. As usedherein, the term “environmental sensor” is used broadly. For example, acanary in a cage, as used by miners to warn of gas, could be consideredan environmental sensor. One or more of the environmental sensors may bea data feed. The data feeds may include, for example, a stock-marketticker, a weather report, a news feed, a traffic-condition update, apublic-health notice, an electronic calendar, a social network newsfeed, another suitable data feed, or two or more such data feeds. Theenvironmental sensors may then transmit one or more data streamscomprising the environmental data to analysis system 180. Analysissystem 180 may then analyze this environmental data by inputting it intoa stress model that correlates environmental states with stress tocalculate the person's stress index. Analysis system 180 may alsoanalyze this environmental data to identify events that may act asstressors on a person. Analysis system 180 may continuously monitor adata stream containing environmental data, thereby allowing it toaccurately measure and monitor exogenous events that may cause stress ina person. Although this disclosure describes measuring and monitoringstress using particular types of environmental sensors, this disclosurecontemplates measuring and monitoring stress using any suitableenvironmental sensors.

In particular embodiments, analysis system 180 may access one or moredata streams from an environmental sensor and one or more of othersensors 112 to measure and monitor stress in a person. The data streamsmay comprise environmental data and one or more of psychological data ofthe person, behavioral of the person, or physiological data of theperson. In particular embodiments, analysis system 180 may access datastreams from an environmental sensor and one or more of a mood sensor, aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, or anaccelerometer. Although this disclosure describes accessing particularsensors 112 and particular data streams to measure and monitor stress ina person, this disclosure contemplates accessing any suitable sensors112 and any suitable data streams to measure and monitor stress in aperson.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stress in aperson. A typical diagnostic test involves generating at least two datasets, wherein the data sets are collected when the environmental statesare different between at least two of the data sets. The data sets mayinclude one or more data sets from one or more sensors 112 in sensorarray 110. As an example and not by way of limitation, a first data setmay be collected when the environmental data indicates a first state,and a second data set may be collected when the environmental dataindicates a second state. As another example and not by way oflimitation, a first data set may be collected when the person is exposedto a particular stressor, and a second data set may be collected whenthe person is not exposed to the particular stressor. As yet anotherexample and not by way of limitation, a first data set may be collectedwhen the person is substantially stressed, and a second data set may becollected when the person is substantially unstressed. As yet anotherexample and not by way of limitation, a first data set may be collectedwhen the person is engaged in a first activity, and a second data setmay be collected when the person is engaged in a second activity.Analysis system 180 may then use the environmental data to deconfoundthe data from other sensors 112 to determine whether measured changes inthe physiological state of a person are caused by stress or non-stressrelated events. The accuracy of determining stress in a person maygenerally be increased as the number of data sets is increased.Therefore, multiple data sets may be generated and analyzed to determinestress in a person. Although this disclosure describes accessingparticular data sets to measure and monitor stress in a person, thisdisclosure contemplates accessing any suitable data sets to measure andmonitor stress in a person.

In particular embodiments, analysis system 180 may access a stress modelof a person. As an example and not by way of limitation, a stress modelmay be an algorithm based on renal-Doppler data and environmental dataand one or more of mood data, heart-rate data, blood-pressure data,pulse-oximetry data, or accelerometer data. As an example and not by wayof limitation, a stress model could be an algorithm based on sensormeasurements made by one or more sensors 112 over some control period.The stress model may include a variety of variables, including data fromone or more data streams and one or more fixed variables. The followingis an example algorithm that analysis system 180 could access thatmodels the stress of a person:f _(sm) =f(D _(env) ¹ ,D _(mood) ² ,D _(HR) ³ ,D _(BP) ⁴ ,D _(SpO2) ⁵ ,D_(acc) ⁶ ,X ¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(env) ¹) is the environmental state,    -   (D_(mood) ²) is the psychological state (mood) of the person,    -   (D_(HR) ³) is the heart rate of the person,    -   (D_(BP) ⁴) is the blood pressure of the person,    -   (D_(SpO2) ⁵) is the blood-oxygen level of the person,    -   (D_(acc) ⁶) is the physical activity (acceleration) of the        person, and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

In particular embodiments, analysis system 180 may analyze data setsfrom the environmental data stream and one or more other data streamswith respect to each other. Analysis system 180 may use any suitableprocess, calculation, or technique to analyze the data streams withrespect to each other. As an example and not by way of limitation,analysis system 180 may compare the first data set and a second data toidentify any changes in the environmental state and to identify anycorresponding changes in physiological state of the person. As anotherexample and not by way of limitation, analysis system 180 may analyzethe data streams and identify data points or data ranges from the datastreams that may be used as inputs into a stress model. In particularembodiments, analysis system 180 may contextualize the environmentaldata with other data, such as, for example, by mapping the data withrespect to each other. As an example and not by way of limitation,analysis system 180 may contextualize environmental data with mood data,heart-rate data, blood-pressure data, pulse-oximetry data, andacceleration data of the person, allowing analysis system 180 toidentify correlations between changes in the environmental data and theother data. Although this disclosure describes particular componentsperforming particular processes to analyze the data streams with respectto the each other, this disclosure contemplates any suitable componentsperforming any suitable processes to analyze the data streams withrespect to the each other.

In particular embodiments, analysis system 180 may determine the currentstress index of a person based on the analysis of a plurality of datasets from the environmental data stream and one or more other datastreams with respect to each other. The stress index may be determinedboth from the environmental state and the physiological or psychologicalstate of the person. As discussed previously, various physiologicalstates may correlate with stress, such as, for example, increased heartrate, increased blood pressure, or decreased blood oxygen. Similarly,various environmental states may correlate with stress, such as, forexample, changes in weather, increased pollen counts, changes inlocation, earthquakes and other natural disasters, changes in elevation,increased noise levels, changes in lighting, increased traffic, declinesin the stock-market, disease outbreaks, or changes in social networkstatus (e.g., de-friending, changing relationship status). Physiologicalresponses that correlate with stress may be caused by particularenvironmental stressors, which may be identified in the environmentaldata. As an example and not by way of limitation, analysis system 180may examine the data streams and identify physiological states thatcorrelate with stress or a lack of stress and identify whether themeasured physiological states correlate with an environmental state.Analysis system 180 may analyze one data set to determine the baselinestress of the person and then analyze another data set to determine thechange in the person's physiological states to determine a currentstress index of the person. Analysis system 180 may determine thecurrent stress index of the person by determining the magnitude thateach of the physiological states correlates with stress or lack ofstress. As an example and not by way of limitation, a low respirationrate may correlate with a low stress index while a high respiration ratemay correlate with a high stress index. As another example and not byway of limitation, a small drop in the stock market may correlate with alow stress index while a large drop in the stock market may correlatewith a high stress index. Although this disclosure describes particularcomponents performing particular processes to determine the currentstress index of a person, this disclosure contemplates any suitablecomponents performing any suitable processes to determine the currentstress index of a person. Moreover, although this disclosure describesanalyzing particular data streams for particular correlations todetermine the current stress index of a person, this disclosurecontemplates analyzing any suitable data streams for any suitablecorrelations to determine the current stress index of a person.

In particular embodiments, analysis system 180 may use a stress model ofa person to determine the current stress index of the person based onthe analysis of data sets from the environmental data stream and one ormore other data streams with respect to each other. As an example andnot by way of limitation, the stress model may directly calculate thestress index of the person, such that f_(sm)=SI, where SI is the stressindex of the person. As another example and not by way of limitation,the stress index of the person may be based on the stress model, suchthat f(f_(sm))=SI. Analysis system 180 may calculate the stress index ofthe person based on the data from the environmental data stream and theother data streams. As an example and not by way of limitation, analysissystem 180 may input data points or data ranges from the environmentaldata stream and the other data streams into the stress model asindependent variables. Analysis system 180 may then calculate the stressindex of the person by solving the stress model. Although thisdisclosure describes particular components performing particularprocesses to determine the current stress index of a person, thisdisclosure contemplates any suitable components performing any suitableprocesses to determine the current stress index of a person. Moreover,although this disclosure describes particular relationships between thestress model of a person and the stress index of the person, thisdisclosure contemplates any suitable relationship between the stressmodel of a person and the stress index of the person.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more additional sensors 112 to measure andmonitor stress in a person. As described previously, analysis system 180may access, for example, a behavioral sensor, an electrocardiograph, aglucocorticoid meter, an electromyograph, a respiration sensor, agalvanic-skin-response sensor, or another suitable sensor 112. Analysissystem 180 may then analyze these additional data streams, allowing itto more accurately measure and monitor the stress of the person, suchas, for example, by deconfounding physiological data caused bynon-stress related events.

FIG. 13 illustrates an example method 1300 for monitoring stress usingenvironmental data. The method begins at step 1310, where analysissystem 180 accesses one or more data streams from a plurality of sensors112. The sensors 112 may comprise an environmental sensor and one ormore of a mood sensor, a heart-rate monitor, a blood-pressure monitor, apulse oximeter, or an accelerometer. The data streams may compriseenvironmental data from the environmental sensor and one or more of mooddata of a person from the mood sensor, heart-rate data of the personfrom the heart-rate monitor, blood-pressure data of the person from theblood-pressure monitor, pulse oximetry data of the person from the pulseoximeter, and accelerometer data of the person from the accelerometer. Afirst data set from the data streams may be collected at a first timeand the environmental data in the first data set may indicate a firststate at the first time. A second data set from the data streams may becollected at a second time and the environmental data in the second dataset may indicate a second state at the second time. At step 1320,analysis system 180 may analyze the first data set and the second dataset with respect to each other. At step 1330, analysis system 180 maydetermine a current stress index of the person based on the analysis ofthe first data set and the second data set with respect to each other.Although this disclosure describes and illustrates particular steps ofthe method of FIG. 13 as occurring in a particular order, thisdisclosure contemplates any suitable steps of the method of FIG. 13occurring in any suitable order. Moreover, although this disclosuredescribes and illustrates particular components carrying out particularsteps of the method of FIG. 13, this disclosure contemplates anysuitable combination of any suitable components carrying out anysuitable steps of the method of FIG. 13.

Calculating and Monitoring a Composite Stress Index

Measuring and quantifying stress levels is difficult because there are avariety of physiological, psychological, behavioral, and environmentalfactors that may contribute to a person's stress response. For example,physiological stress represents a wide range of physical responses thatoccur as a direct result of a stressor causing an upset in thehomeostasis of the body. Upon immediate disruption of eitherpsychological or physiological equilibrium, the body responds bystimulating the nervous, endocrine, and immune systems. The reaction ofthese systems causes a number of physiological changes that have bothshort-term and long-term effects on the body. However, physiologicalstress may be caused internally or by psychological, behavioral, orenvironmental factors. Therefore, a composite stress index capable ofquantifying stress caused by a variety of sources is needed.

Particular stressors may be associated with particular changes in thestress index of a person (i.e., stress factors). For example, one couldhave a “meeting stress factor,” a “traffic stress factor,” a“social-engagement stress factor,” an “economic-change stress factor,”and so on. Therefore, the stress index may be calibrated with respect tospecific stressors. Each person may have personalized responses andrecovery patterns for each type of stressor, indicating a variety ofstress factors and stress resilience coefficients. Analysis system 180may be used to measure and monitor stress factors and stress resilience.This may allow a user to determine the types of stressors that lead todifferent resilience patterns in a given individual or population, whichmay be useful for helping with stress management.

In particular embodiments, a stress factor may be assigned to aparticular stressor. A stress factor is the change in a person's stressindex associated with a particular stressor or therapy. Thus, a person'sstress after being exposed to a particular stressor is based on theperson's stress before being exposed to the particular stressor and thestress factor associated with the stressor. As an example and not by wayof limitation, a person's current stress index may be SI=f(SI₀, SF_(i)),where SI is the current stress index of the person, SI₀, is the stressindex of the person before being exposed to stressor i, and SF_(i) isthe stress factor associated with stressor i. In particular embodiments,the stress factor may be added to the prior stress index of a person tocalculate a current stress index. As an example and not by way oflimitation, a minor stressor, such a attempting to solve relativelysimple mathematical questions, may increase a person's stress index by 5points on a 0-to-100 stress scale, while a major stressor, such as havean argument with one's spouse, may increase a person's stress index by20 points on the same stress scale. Thus, the minor stress would beassigned a stress factor of (+5)/100 and the major stressor would beassigned a stress factor of (+20)/100. In particular embodiments, thestress factor may be used to perform a mathematical operation other thansimple linear addition (such as, for example, multiplication, division,exponentiation, negation, trigonometric function, or other suitablemathematical operations) or be used as part of a mathematical functionto calculate the current stress index of a person. Although thisdisclosure describes assigning particular stress factors with particularstressors, this disclosure contemplates assigning any suitable stressfactors with any suitable stressors.

In particular embodiments, analysis system 180 may measure and monitorstressors by analyzing data streams from the following three groups ofsensors 112: (1) one or more physiological sensors; (2) one or moredeconfounding sensors; and (3) one or more stressor sensors. Analysissystem 180 may measure one or more physiological parameters from thesensors 112 in the first group. Then data from the sensors 112 in thesecond group may be used to deconfound the physiological data from thefirst group to determine whether physiological changes are actuallycaused by stress and not a non-stress related event. Finally, the datafrom the sensors 112 in the third group may measure changes inpsychological, behavioral, or environmental states that may act asstressors. After the sensors 112 in the three groups take appropriatemeasurements, the sensors 112 may then transmit one or more data streamscomprising the user's physiological data and other data to analysissystem 180. Analysis system 180 may then analyze the data from the firstand second groups of sensors 112 by inputting it into a stress modelthat correlates physiological data and other data with stress tocalculate the person's stress index and the change in stress indexcaused by a stressor. By isolating the stress index measurement to thefirst and second groups of sensors 112, the change in stress indexcaused by a particular stressor (as measured by the sensors 112 from thethird group) can be accurately determined. Analysis system 180 maycontinuously monitor data streams from the three groups of sensors 112,thereby allowing it to accurately measure and monitor the person'sstress and stress-related health states. Although this disclosuredescribes measuring and monitoring stressors using particular types andgroups of sensors 112, this disclosure contemplates measuring andmonitoring stressors using any suitable types or groups of sensors 112.

In particular embodiments, analysis system 180 may access one or moredata streams from a first, second, and third group of sensors 112 tomeasure and monitor stressors. The data streams may comprisephysiological data of the person, psychological data of the person,behavioral data of the person, or environmental data. In particularembodiments, analysis system 180 may access data streams from one ormore first sensors selected from a first group of sensor typesconsisting of a heart-rate monitor, a blood-pressure monitor, a pulseoximeter, and an accelerometer. These first sensors may transmit datastreams comprising heart-rate data of the person, blood-pressure data ofthe person, pulse-oximeter data of the person, and accelerometer data ofthe person, respectively. In particular embodiments, analysis system 180may access data streams from one or two second sensors selected from asecond group of sensor types consisting of a mood sensor, a behavioralsensor, and an environmental sensor. These second sensors may transmitmood data of the person, behavioral data of the person, andenvironmental data, respectively. In particular embodiments, analysissystem 180 may access data streams from one third sensor selected fromthe second group of sensor types, where the third sensor is of adifferent sensor type than any of the second sensors. As an example andnot by way of limitation, if the second sensors are a mood sensor and abehavioral sensor, then the third sensor may only be an environmentalsensor. As another example and not by way of limitation, if the secondsensor is a mood sensor, then the third sensor may be either abehavioral sensor or an environmental sensor. Although this disclosuredescribes accessing particular sensors 112 and particular data streamsto measure and monitor stressors, this disclosure contemplates accessingany suitable sensors 112 and any suitable data streams to measure andmonitor stressors.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stressors. Atypical diagnostic test involves generating at least two data sets,wherein the data sets are collect from the person when he is exposed toa particular stressor and then not exposed to a particular stressor. Thedata sets may include one or more data sets from one or more sensors 112in sensor array 110. As an example and not by way of limitation, a firstdata set may be collected from the person when the person is exposed toa particular stressor (e.g., arguing), and a second data set may becollected from the person when the person is not exposed to theparticular stressor. As another example and not by way of limitation, afirst data set may be collected from the person when the person issubstantially stressed, and a second data set may be collected from theperson when the person substantially unstressed. As yet another exampleand not by way of limitation, a first data set my be collected from theperson when the person is engaged in a first activity that may bestressful, and a second data set may be collected from the person whenthe person is engaged in a second activity that may not be stressful.Analysis system 180 may then use the data from the second group ofsensors 112 to deconfound the data from the first group of sensors 112to determine whether measured changes in the physiological state of aperson are caused by a stressor (as measured by data from the thirdgroup of sensors 112) or a non-stress related event (e.g., physicalmotion of the person). The accuracy of determining a stress factor for aparticular stressor may generally be increased as the number of datasets is increased. Therefore, multiple data sets may be generated andanalyzed to determine a stress factor for a stressor. Although thisdisclosure describes accessing particular data sets to measure andmonitor stressors, this disclosure contemplates accessing any suitabledata sets to measure and monitor stressors.

In particular embodiments, analysis system 180 may access a stress modelof a person. As an example and not by way of limitation, a stress modelmay be an algorithm based on renal-Doppler data and two or more ofheart-rate data, blood-pressure data, pulse-oximetry data, or mood data.As an example and not by way of limitation, a stress model could be analgorithm based on sensor measurements made by one or more sensors 112over some control period. The stress model may include a variety ofvariables, including data from one or more data streams and one or morefixed variables. The following is an example algorithm that analysissystem 180 could access that models the stress of a person:f _(sm) =f(D _(HR) ¹ ,D _(BP) ² ,D _(SpO2) ³ ,D _(acc) ⁴ ,D _(mood) ⁵ ,D_(beh) ⁶ ,D _(env) ⁷ ,X ¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(HR) ¹) is the heart rate of the person,    -   (D_(BP) ²) is the blood pressure of the person,    -   (D_(SpO2) ³) is the blood-oxygen level of the person,    -   (D_(acc) ⁴) is the physical activity (acceleration) of the        person,    -   (D_(mood) ⁵) is the psychological state (mood) of the person,    -   (D_(beh) ⁶) is the behavioral state (activity) of the person,    -   (D_(env) ⁷) is the environmental state and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

In particular embodiments, analysis system 180 may analyze data setsfrom the data streams from the first, second, and third groups ofsensors 112 with respect to each other. Analysis system 180 may use anysuitable process, calculation, or technique to analyze the data streamswith respect to each other. As an example and not by way of limitation,analysis system 180 may compare the first data set and a second data toidentify any changes in the physiological state the person and toidentify any corresponding changes in psychological, behavioral, orenvironmental state. As another example and not by way of limitation,analysis system 180 may analyze the data streams and identify datapoints or data ranges from the data streams that may be used as inputsinto a stress model. In particular embodiments, analysis system 180 maycontextualize the physiological data with other data, such as, forexample, by mapping the data with respect to each other. As an exampleand not by way of limitation, analysis system 180 may contextualizephysiological data of the person with psychological, behavioral, orenvironmental data, allowing analysis system 180 to identifycorrelations between changes in the physiological data and the otherdata. Although this disclosure describes particular componentsperforming particular processes to analyze the data streams with respectto the each other, this disclosure contemplates any suitable componentsperforming any suitable processes to analyze the data streams withrespect to the each other.

In particular embodiments, analysis system 180 may determine the currentstress factor for a stressor based on the analysis of a plurality ofdata sets from the data streams from the first, second, and third groupsof sensors 112 with respect to each other. The stress factor may bedetermined both from the physiological data of the person and thepsychological, behavioral, and environmental data. As discussedpreviously, various physiological states may correlate with stress, suchas, for example, increased heart rate, increased blood pressure, ordecreased blood oxygen. However, these same physiological states mayalso be caused by non-stress related events. As an example and not byway of limitation, analysis system 180 may examine the data streams fromthe first group of sensors 112 and identify physiological states thatcorrelate with stress or a lack of stress, identify whether the measuredphysiological states were caused by a non-stress related event asmeasured by the second group of sensors 112, and identify whether themeasured physiological states correlate with a stress event as measureby the third group of sensors 112. Analysis system 180 may analyze onedata set to determine the baseline stress of the person and then analyzeanother data set to determine the change in the person's physiologicalstates to determine the change in the stress index of the person andthereby the stress factor for the stressor measured by the third groupof sensors 112. Although this disclosure describes particular componentsperforming particular processes to determine the current stress factorfor a stressor, this disclosure contemplates any suitable componentsperforming any suitable processes to determine the current stress factorfor a stressor. Moreover, although this disclosure describes analyzingparticular data streams for particular correlations to determine thecurrent stress factor for a stressor, this disclosure contemplatesanalyzing any suitable data streams for any suitable correlations todetermine the current stress factor for a stressor.

In particular embodiments, analysis system 180 may use a stress model ofa person to determine the current stress factor for a stressor based onthe analysis of data sets from the data streams from the first, second,and third groups of sensors 112 with respect to each other. As anexample and not by way of limitation, the stress model may directlycalculate the stress index of the person, such that f_(sm)=SI, where SIis the stress index of the person. As another example and not by way oflimitation, the stress index of the person may be based on the stressmodel, such that f(f_(sm))=SI. Analysis system 180 may calculate thestress index of the person based on the data from the physiological datastreams and the other data streams. As an example and not by way oflimitation, analysis system 180 may input data points or data rangesfrom the data streams from the first and second group of sensors 112into the stress model as independent variables. Analysis system 180 maycalculate the stress index of the person at the first time and thesecond time by solving the stress model. Analysis system 180 may thencalculate the stress factor of the stressor measured by the third sensorby calculating the change in the stress index of the person from thefirst time to the second time. Although this disclosure describesparticular components performing particular processes to determine thecurrent stress factor for a stressor, this disclosure contemplates anysuitable components performing any suitable processes to determine thecurrent stress factor for a stressor.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more additional sensors 112 to measure andmonitor stressors. As described previously, analysis system 180 mayaccess, for example, an electrocardiograph, a glucocorticoid meter, anelectromyograph, a respiration sensor, a galvanic-skin-response sensor,or another suitable sensor 112. Analysis system 180 may then analyzethese additional data streams, allowing it to more accurately measureand monitor the stressors, such as, for example, by deconfoundingphysiological data caused by non-stress related events.

FIG. 14 illustrates an example method 1400 for calculating a stressfactor for a stressor. The method begins at step 1410, where analysissystem 180 accesses one or more data streams from a plurality of sensors112. The sensors 112 may comprise one or more first sensors selectedfrom a first group of sensor types consisting of a heart-rate monitor, ablood-pressure monitor, a pulse oximeter, and an accelerometer. Thesensors 112 may further comprise one or two second sensors selected froma second group of sensor types consisting of a mood sensor, a behavioralsensor and an environmental sensor. The sensors 112 may further comprisea third sensor also selected from the second group of sensor types. Thethird sensor is different in sensor type from each of the two secondsensors. The data streams comprise one or more of heart-rate data of aperson from the heart-rate monitor, blood-pressure data of the personfrom the blood-pressure monitor, pulse-oximetry data of the person fromthe pulse oximeter, accelerometer data of the person from theaccelerometer, mood data of the person from the mood sensor, behavioraldata of the person from the behavioral sensor, or environmental datafrom the environmental sensor. A first data set from the data streamsmay be collected from the person at a first time and the person may beexposed to a stressor at the first time, as indicated by data in thefirst data set from the third sensor. A second data set from the datastreams may be collected from the person at a second time and the personmay not have been exposed to the stressor at the second time, asindicated by data in the second data set from the third sensor. At step1420, analysis system 180 may analyze the first data set and the seconddata set with respect to each other. At step 1430, analysis system 180may determine a current stress factor for the stressor with respect tothe person based on the analysis of the first data set and the seconddata set with respect to each other. Although this disclosure describesand illustrates particular steps of the method of FIG. 14 as occurringin a particular order, this disclosure contemplates any suitable stepsof the method of FIG. 14 occurring in any suitable order. Moreover,although this disclosure describes and illustrates particular componentscarrying out particular steps of the method of FIG. 14, this disclosurecontemplates any suitable combination of any suitable componentscarrying out any suitable steps of the method of FIG. 14.

Calculating and Monitoring the Efficacy of Stress-Related Therapies

Another problem with measuring and monitoring stress accurately isdetermining whether particular stress-reduction therapies are effective.Many different techniques for stress reduction exist. Quantifying theeffectiveness of stress reduction may be done by contextualizing thetherapy with a variety of data, such as, for example, physiological,psychological, behavioral, or environmental data. An appropriate stressmanagement approach may differ based upon the nature of the stressor orthe person. For example, for a particular person, breathing exercisesmay be more effective than cognitive reframing when the stress is causedby a domestic argument, while the reverse may be true when the stress iscause by work-related stress. Consequently, a system capable ofquantifying the effectiveness of stress reduction techniques for aparticular person is needed.

Particular therapies may be associated with particular changes in thestress index of a person (i.e., stress factors). For example, one couldhave a “meditation stress factor,” a “biofeedback stress factor,” a“cognitive reframing stress factor,” an “intervention stress factor,”and so on. Therefore, the stress index may be calibrated with respect tospecific therapies. Each person may have personalized responses andrecovery patterns for each type of therapy, indicating a variety ofstress factors and stress resilience coefficients. Analysis system 180may be used to measure and monitor stress factors and stress resilience.This may allow a user to determine the types of therapies that are mosteffective in a given individual or population, which may be useful forhelping with stress management.

In particular embodiments, a stress factor may be assigned to particulartherapy. A stress factor is the change in a person's stress indexassociated with a particular stressor or therapy. As an example and notby way of limitation, a minor therapy, such a short breathing exercise,may decrease a person's stress index by 8 points on a 0-to-100 stressscale, while a therapy stressor, such as an hour of meditation, maydecrease a person's stress index by 30 points on the same stress scale.Thus, the minor therapy would be assigned a stress factor of (−8)/100and the major stressor would be assigned a stress factor of (−30)/100.Although this disclosure describes assigning particular stress factorswith particular stressors, this disclosure contemplates assigning anysuitable stress factors with any suitable stressors.

In particular embodiments, a person may engage in a variety ofstress-related therapies. Stress-related therapies may include, forexample, interventions, biofeedback, breathing exercises, progressivemuscle relaxation exercises, presentation of personal media (e.g.,music, personal pictures, etc.), offering an exit strategy (e.g.,calling the user so he has an excuse to leave a stressful situation),references to a range of psychotherapeutic techniques, and graphicalrepresentations of trends (e.g., illustrations of health metrics overtime), cognitive reframing therapy, other suitable stress-relatedtherapies, or two or more such therapies. A person may receive astress-related therapy in a variety of ways, such as, for example, froma third-person (e.g., a physician or therapist), from himself (e.g.,self-relaxation techniques), from display system 190 (e.g., displaying astress-related therapy), or from another suitable source. Analysissystem 180 may receive input describing the therapies, such as the type,duration, and source of the therapy. Analysis system 180 may thencontextualize stress index data with the therapy data to calculate thestress factor for the therapy. Although this disclosure describesparticular therapies, this disclosure contemplates any suitabletherapies.

In particular embodiments, analysis system 180 may measure and monitorstress-related therapies by analyzing one or more data streams from oneor more sensors 112, such as, for example, an accelerometer, aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, a moodsensor, a behavioral sensors, an environmental sensor, or anothersuitable sensor 112. These sensors 112 may be used to measure the stressindex of a person, as described previously. After the sensors 112 takeappropriate measurements, the sensors 112 may then transmit one or moredata streams comprising the user's physiological, psychological,behavioral, or environmental data to analysis system 180. Analysissystem 180 may then analyze this data by inputting it into a stressmodel that correlates physiological, psychological, behavioral, orenvironmental data with stress to calculate the person's stress index.Analysis system 180 may continuously monitor data streams from thesensors 112, thereby allowing it to accurately measure and monitor theperson's stress, stress-related health states, and stress index.Although this disclosure describes measuring and monitoringstress-related therapies using particular types of sensors 112, thisdisclosure contemplates measuring and monitoring stress-relatedtherapies using any suitable types of sensors 112.

In particular embodiments, analysis system 180 may access two or moredata streams two or more sensors 112 to measure and monitorstress-related therapies. The data streams may comprise physiologicaldata of the person, psychological data of the person, behavioral data ofthe person, or environmental data. In particular embodiments, analysissystem 180 may access data streams from two or more of an accelerometer,a heart-rate monitor, a blood-pressure monitor, a pulse oximeter, or amood sensor. Although this disclosure describes accessing particularsensors 112 and particular data streams to measure and monitorstress-related therapies, this disclosure contemplates accessing anysuitable sensors 112 and any suitable data streams to measure andmonitor stress-related therapies.

In particular embodiments, analysis system 180 may access a plurality ofdata sets from the data streams to measure and monitor stress-relatedtherapies. A typical diagnostic test involves generating at least twodata sets, wherein the data sets are collect from the person when he isengaged in a particular therapy and then not engaged in a particulartherapy. The data sets may include one or more data sets from one ormore sensors 112 in sensor array 110. As an example and not by way oflimitation, a first data set may be collected from the person when theperson is engaged in a particular therapy (e.g., meditation), and asecond data set may be collected from the person when the person is notengaged in the particular therapy. As another example and not by way oflimitation, a first data set may be collected from the person when theperson is substantially stressed, and a second data set may be collectedfrom the person when the person substantially unstressed. As yet anotherexample and not by way of limitation, a first data set my be collectedfrom the person when the person is engaged in a first activity that maybe relaxing (i.e., a stress-related therapy), and a second data set maybe collected from the person when the person is engaged in a secondactivity that may not be relaxing. Analysis system 180 may thendetermine whether measured changes in the physiological state of aperson are caused by a stress-related therapy or a non-stress relatedevent (e.g., ceasing physical activity). The accuracy of determining astress factor for a particular stress-related therapy may generally beincreased as the number of data sets is increased. Therefore, multipledata sets may be generated and analyzed to determine a stress factor fora stress-related therapy. Although this disclosure describes accessingparticular data sets to measure and monitor stress-related therapies,this disclosure contemplates accessing any suitable data sets to measureand monitor stress-related therapies.

In particular embodiments, analysis system 180 may access a stress modelof a person. As an example and not by way of limitation, a stress modelmay be an algorithm based on renal-Doppler data and two or more ofaccelerometer data, heart-rate data, blood-pressure data, pulse-oximetrydata, or mood data. As an example and not by way of limitation, a stressmodel could be an algorithm based on sensor measurements made by one ormore sensors 112 over some control period. The stress model may includea variety of variables, including data from one or more data streams andone or more fixed variables. The following is an example algorithm thatanalysis system 180 could access that models the stress of a person:f _(sm) =f(D _(acc) ¹ ,D _(HR) ² ,D _(BP) ³ ,D _(SpO2) ⁴ ,D _(mood) ⁵ ,X¹ , . . . ,X ^(M))

where:

-   -   f_(sm) is the stress model,    -   (D_(acc) ¹) is the physical activity (acceleration) of the        person,    -   (D_(HR) ²) is the heart rate of the person,    -   (D_(BP) ³) is the blood pressure of the person,    -   (D_(SpO2) ⁴) is the blood-oxygen level of the person,    -   (D_(mood) ⁵) is the psychological state (mood) of the person,        and    -   (X¹, . . . , X^(M)) are fixed variables 1 through M.

Although this disclosure describes accessing particular stress modelsbased on particular data or variables, this disclosure contemplatesaccessing any suitable stress models based on any suitable data orvariables.

In particular embodiments, analysis system 180 may analyze data setsfrom the data with respect to each other. Analysis system 180 may useany suitable process, calculation, or technique to analyze the datastreams with respect to each other. As an example and not by way oflimitation, analysis system 180 may compare the first data set and asecond data to identify any changes in the physiological state theperson and to identify any corresponding changes in psychological,behavioral, or environmental state. As another example and not by way oflimitation, analysis system 180 may analyze the data streams andidentify data points or data ranges from the data streams that may beused as inputs into a stress model. In particular embodiments, analysissystem 180 may contextualize the physiological data with other data,such as, for example, by mapping the data with respect to each other. Asan example and not by way of limitation, analysis system 180 maycontextualize physiological data of the person with psychological,behavioral, or environmental data, allowing analysis system 180 toidentify correlations between changes in the physiological data and theother data. Although this disclosure describes particular componentsperforming particular processes to analyze the data streams with respectto the each other, this disclosure contemplates any suitable componentsperforming any suitable processes to analyze the data streams withrespect to the each other.

In particular embodiments, analysis system 180 may determine the currentstress factor for a stress-related therapy based on the analysis of aplurality of data sets from the data streams with respect to each other.The stress factor may be determined both from the physiological,psychological, behavioral, and environmental data from the sensors 112in sensor array 110. As discussed previously, various physiologicalstates may correlate with stress, such as, for example, increased heartrate, increased blood pressure, or decreased blood oxygen. However,these same physiological states may also be caused by non-stress relatedevents. As an example and not by way of limitation, analysis system 180may examine the data streams and identify physiological states thatcorrelate with stress or a lack of stress, identify whether the measuredphysiological states were caused by a non-stress related event asmeasured by the second group of sensors 112, and identify whether themeasured physiological states correlate with a stress-related therapy.Analysis system 180 may analyze one data set to determine the baselinestress of the person and then analyze another data set to determine thechange in the person's physiological states to determine the change inthe stress index of the person and thereby the stress factor for thestress-related therapy. Although this disclosure describes particularcomponents performing particular processes to determine the currentstress factor for a stress-related therapy, this disclosure contemplatesany suitable components performing any suitable processes to determinethe current stress factor for a stress-related therapy. Moreover,although this disclosure describes analyzing particular data streams forparticular correlations to determine the current stress factor for astress-related therapy, this disclosure contemplates analyzing anysuitable data streams for any suitable correlations to determine thecurrent stress factor for a stress-related therapy.

In particular embodiments, analysis system 180 may use a stress model ofa person to determine the current stress factor for a therapy based onthe analysis of data sets from the data streams with respect to eachother. As an example and not by way of limitation, the stress model maydirectly calculate the stress index of the person, such that f_(sm)=SI,where SI is the stress index of the person. As another example and notby way of limitation, the stress index of the person may be based on thestress model, such that f(f_(sm))=SI. Analysis system 180 may calculatethe stress index of the person based on the data from the data streams.As an example and not by way of limitation, analysis system 180 mayinput data points or data ranges from the data streams into the stressmodel as independent variables. Analysis system 180 may calculate thestress index of the person at the first time and second time by solvingthe stress model. Analysis system 180 may then calculate the stressfactor of the therapy by calculating the change in the stress index ofthe person from the first time to the second time. Although thisdisclosure describes particular components performing particularprocesses to determine the current stress index of a person, thisdisclosure contemplates any suitable components performing any suitableprocesses to determine the current stress index of a person.

In particular embodiments, analysis system 180 may access one or moredata streams from one or more additional sensors 112 to measure andmonitor stress-related therapies. As described previously, analysissystem 180 may access, for example, a kinesthetic sensor, a behavioralsensor, an electrocardiograph, a glucocorticoid meter, anelectromyograph, a respiration sensor, a galvanic-skin-response sensor,or another suitable sensor 112. Analysis system 180 may then analyzethese additional data streams, allowing it to more accurately measureand monitor the stress-related therapies, such as, for example, bydeconfounding physiological data caused by non-stress related events.

FIG. 15 illustrates an example method 1500 for calculating a stressfactor for a therapy. The method begins at step 1510, where analysissystem 180 accesses one or more data streams from a plurality of sensors112. The sensors 112 may comprise two or more of an accelerometer, aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, or amood sensor. The data streams may comprise two or more of accelerometerdata of a person from the accelerometer, heart-rate data of the personfrom the heart-rate monitor, blood-pressure data of the person from theblood-pressure monitor, pulse-oximetry data of the person from the pulseoximeter, or mood data of the person from the mood sensor. A first dataset from the data streams may be collected from the person at a firsttime and the person may be engaged in a therapy at the first time. Asecond data set from the data streams may be collected from the personat a second time and the person may not have engaged in the therapy atthe second time. At step 1520, analysis system 180 may analyze the firstdata set and the second data set with respect to each other. At step1530, analysis system 180 may determine a current stress factor for thetherapy on the person based on the analysis of the first data set andthe second data set with respect to each other. Although this disclosuredescribes and illustrates particular steps of the method of FIG. 15 asoccurring in a particular order, this disclosure contemplates anysuitable steps of the method of FIG. 15 occurring in any suitable order.Moreover, although this disclosure describes and illustrates particularcomponents carrying out particular steps of the method of FIG. 15, thisdisclosure contemplates any suitable combination of any suitablecomponents carrying out any suitable steps of the method of FIG. 15.

Example 1

In this experiment, changes in either the renal blood flow in the mainrenal artery or in the intra-renal artery were measured in a patient inrelaxed and stressed states. Renal blood flow was measured using arenal-pulse Doppler. Most readings were taken on the renal artery, as itis assumed that the best and most stable change in renal blood flow isreflected in the main artery near the kidney. The hypothesis for theseexperiments was that renal resistive index (renal RI) will increase withstress and decrease with relaxation.

Measurement Strategy: The first measurement is taken as soon as theexperiment starts. This reading acts as a baseline renal blood flow. Inthis reading, the stress state is not known, and the patient may be in astressed or relaxed state. After taking the initial reading, the patientis asked to relax (i.e., self-relaxation). In this method, the patientattempts to relax by himself with no external disturbance provided. Theperson is then asked to signal when he feels relaxed. After the personsignals, another measurement is taken. After taking the measurements,the person is subjected to forced relaxation, which can include talking,telling jokes, etc. After the forced relaxation, another measurement istaken. Next, the person is then subjected to forced stress. The stressmay be induced by asking the patient mathematical problems and askinghim to orally solve the problems. After the forced stress, anothermeasurement is taken. Next, the patient is again subjected to forcedrelaxation, and then a measurement is again taken. Finally, the patientis again subjected to forced stress by asking the patient personalquestions that are intended to induce stress. After the personalquestion, a measurement is taken. The measurement strategy ensures thatthe stress in the person is recorded, and the change from one state toanother is also recorded. This should also the impact of variousstressors to be discretely analyzed.

Measurement Process: In order to take renal-pulse Doppler measurement inthe intra-renal artery, the patient is asked to hold his breath. Duringthis time, the technician focuses on the major artery and takes themeasurement. After taking the measurement, the patient can breathenormally. As soon as the question is asked, the patient is again askedto hold his breath and another measurement is taken. This measurementprocess may be repeated up to five times and the average of themeasurement is taken as the reading. The renal-pulse Doppler measurementis used to analyze renal vascular resistance. In the present equipment,a technician manually selects the peak and the trough from the pulsewaveform. The machine then uses the peak and trough to calculate theresistive index (RI), which gives an indication of the renal vascularresistance (RVR). The resistive index is calculated from the peaksystolic velocity and the lowest diastolic velocity. The peaks andtroughs can be identified from the Doppler waveform. RI is equal to thepeak systolic velocity (S) minus the lowest diastolic velocity (D),divided by the peak systolic velocity (S). Thus,

${RI} = {\frac{S - D}{S}.}$The systolic-to-diastolic flow velocities ratio (S/D ratio) is the ratioof the systolic velocity peak and the diastolic velocity trough. Thus,

${S/D} = {\frac{1}{1 - {RI}}.}$The renal vascular resistance (RVR) is equal to the pressure differenceof renal arterial blood pressure (P_(a)) minus renal venous bloodpressure (P_(v)), divided by the renal blood flow (F). Thus,

${RVR} = {\frac{P_{a} - P_{v}}{F}.}$

The pulse Doppler can be taken over an area, which is properly focused.In order to focus the pulse Doppler, external movement should beeliminated. In particular, breathing can cause the kidneys to move up toa half-inch. Due to this movement, a pulse Doppler measurement cannot betaken accurately when the patient is breathing normally. Thus, thepatient must hold his breath during the measurement. It is alsoimportant to focus the pulse Doppler on the major artery in the kidneyfor each measurement. The same artery must be used for each measurementbecause the RI can be different in different arteries. Also, the anglebetween the beam and the direction of blood flow should be minimized inorder to increase the accuracy of the measurement. Furthermore, themeasurement angle should be kept constant between measurements.Consequently, the location and angle of all measurements should be thesame.

Patient History: The patient is 23-years old, with no smoking ordrinking habits. There is no personal or family history of hypertension,heart disease, or kidney diseases. The patient has good analyticalskills and relatively poor oral arithmetic skills.

Results:

State 1: The patient's RI was measured in a normal (baseline) statewithout any forced stress or relaxation. The patient'ssystolic-to-diastolic flow velocities ratio (S/D) was also measured.During this initial measurement, the patient reported that he wasfeeling stressed caused by anxiety over the trial as well as the feelingthat time is being wasted by lying idle. The measurements in state 1were:

So. No. 1 2 3 Average RI 0.61 0.64 0.61 0.62 S/D Ratio 2.56 2.79 2.572.64

State 2: The patient was subjected to forced relaxation by talking andtelling jokes. The readings were then taken after every short event offorced relaxation. The patient reported that he was not relaxed by theforced relaxation and that he still felt the same as in state 1. Themeasurements in state 2 were:

So. No. 1 2 3 4 Average RI 0.62 0.63 0.62 0.62 0.62 S/D Ratio 2.63 2.702.66 2.61 2.65

State 3: The patient was asked some simple arithmetic questions andmeasurements after asking the questions. Then the patient was asked torelax. The patient reported that he was feeling relaxed and that he wasfeeling less anxiety about the trial. Because the questions wererelatively simple, the person was relaxed while answering. Then thepatient was asked difficult arithmetic questions. The patient took moretime to answer the difficult questions. The patient reported that thedifficult question increased his stress because he was attempting toanswer the difficult questions as quickly as he answered the simplequestions. The patient was then asked to relax, however, this did notmake the patient any more relaxed as he was already feeling relaxed. Themeasurements in state 3 were:

So. No. 1.1 1.2 1.3 2 3 4.1 4.2 4.3 4.4 5.1 5.2 5.3 Average RI 0.57 0.510.48 0.62 0.67 0.59 0.55 0.50 0.54 0.53 0.51 0.50 0.55 S/D 2.33 2.061.94 2.61 2.80 2.46 2.25 2.00 2.18 2.11 2.02 2.00 2.22 Ratio

State 4: The patient was asked some personal questions that wereintended to cause stress. The patient reported feeling slightly stressedwhen answering the personal questions. However, the stressed variedquestion to question. For example, one question increased the patient'sstress, while the last question actually relaxed the patient as hediscussed a particular issue.

So. No. 1 2 3 4 5 Average RI 0.59 0.57 0.63 0.60 0.57 0.59 S/D Ratio2.47 2.33 2.73 2.5 2.33 2.47

Summary of the Trial: The patient's pulse Doppler was measured in eitherthe renal artery or intra-renal artery. Intra-renal artery is likelymore responsive to stress, however is it also more sensitive to motion,making it more difficult to take an accurate measurement. The patienthad to hold his breath for measurements to be taken, which wasdetrimental to the experiment. Thus for the further experiments, themain renal Doppler at the start of the renal artery was used. In mainrenal artery Doppler the measurement is taken from the renal artery at alocation beneath stomach instead of at the kidney. Respiration causesless movement at this location, thus making it substantially easier totake measurements without making the patient hold his breath.Furthermore, relatively continuous measurements can be taken at thislocation, such that changes in RI and S/D ration can be measuredeffectively as soon as they occur.

Summary: Renal Doppler measurements were taken on the renal artery orintra-renal artery. For the intra-renal artery, the person needed tohold his breath for measurement. Peaks and troughs in the waveform wereselected manually. Stress was induced by asking the patient mathematicaland personal questions. Changes in RI correlated with the patient'sself-reported stress level, such that RI increased with stress.

State Average RI Inference Normal 0.62 Initial anxious state. Forcedrelaxation 0.62 No effect on stress level. Mathematical Questions 0.53RI decreased due to focus in mind. Personal Questions 0.59 RI lower thannormal state.

Example 2

In this experiment, the measurement strategy remained the same as usedin example 1. The only difference was that patient did not need to holdhis breath during measurements. This second experiment aims to confirmthe results of RI dependence on stress and observe if some othercorrelation is seen between the stress and renal blood flow. New Dopplerequipment was used in this experiment which was able to automaticallyidentify peaks and troughs in waveforms, allowing for more accuratemeasurements. The patient in this experiment was the same as fromexperiment 1. In this experiment, the person was asked questionscontinuously and only a brief time period was given to relax betweeneach question. This allowed for measurement of the time needed for aperson to recover from stress and particular stressors. Thisstress-recovery time is inversely proportional to the extent ofcompensatory mechanism of that person.

Results:

1. Baseline measurement (normal state): RI=0.65, 0.64.

2. After asking tough algebraic questions: RI=0.72, 0.70, 0.71.

3. After giving a brief time for relaxation: RI=0.61.

4. During and after asking the mathematical question: RI=0.70, 0.70,0.71, 0.70, 0.72.

5. After giving a brief time for relaxation along with deep breathingexercise: RI=0.62, 0.62, 0.61.

6. Before asking analytical questions: RI=0.66.

7. Asking the analytical questions: RI=0.72, 0.69, 0.64, 0.66, 0.69,0.74.

8. Asking the arithmetic questions: RI=0.74, 0.72, 0.73.

9. The person is asked to undergo self induced stress. RI=0.77, 0.81,0.84.

10. Return to baseline measurement (normal state): RI=0.66, 0.69, and0.72.

During the continuous measurements, it was observed that it took only10-12 pulses for the patient to return to a normal (i.e. relaxed) state.This demonstrated the extent of the patient's compensatory mechanismsfor dealing with stress. This also indicates that delays in makingmeasurements may cause erroneous RI measurement. Consequently,measurements should be taken immediately after stress is induced.

The Doppler waveform varied with the patient's stress level. It wasobserved that the peaks in the waveform became sharper and the areaunder the peak decreased as the patient's stress increased.

When the patient was asked analytical questions (state 7), a goodcorrelation was observed between the question asked and the RI increase.RI increased more with more difficult questions. It was also observedthat RI increased just prior to or during question dictation. However,if the question was simple, the patient's RI would decrease immediatelyafter the question was completed. This demonstrates that merely asking aquestion, regardless of the content of a question, may cause stress.

When the patient was asked to self-induce stress (state 9), the patientwas instructing to think of a stressful past-experience or any probablestressful future-event. The patient then signaled once he felt stressed.

When the patient returned to a normal state (state 10), it was expectedthat the patient's RI would return to the level observed during thebaseline measurement (state 1). This was not observed, however, likelybecause the person was asked to hold his breath during this finalmeasurement, which may have cause the patient's stress and RI toincrease.

The patient's average RI when relaxed was 0.62 and his average RI whenstressed was 0.75. There is a significant difference of 21% in theaverage readings. There is also a difference of 38% in min value ofrelaxed and max value in stressed.

Summary: Renal Doppler measurements were taken on the main renal artery.The patient did not need to hold his breath. Peaks and troughs wereselected automatically, and RI was also calculated automatically. Thisallowed for more accurate RI measurements than in experiment 1. Changesin RI correlated with the patient's self-reported stress level, suchthat RI increased with stress.

State Average RI Inference Normal 0.64 Initial state Relaxed 0.61 RIdecreased Forced Relaxation 0.62 Deep breathing decreased RI and stressMathematical Questions 0.71 Increased RI confirms stress Self-inducedStress 0.81 Large RI indicating high stress

Example 3

The trial of example 2 was repeated on a new patient.

Measurement Strategy: The patient is asked to relax for some time. Thepatient is not told about the procedure or the type of questions thatwill be asked. The person is then asked some simple mathematicalquestions (e.g., addition and subtraction). The patient is then askedmore complicated mathematical questions (e.g., multiplication anddivision). The patient is also asked some personal and job-relatedquestions that are intended to induce stress. Renal Doppler measurementsare taken continuously as the questions are asked.

Patient History: The patient is 35-years old, with no history of heartdisease or kidney disease. The patient has poor mathematical skills. Thepatient did not complete the high school and is not fond of mathematics.The examining physician knew certain personal details about the patient.

Results:

1. Baseline measurement (normal state): RI=0.60, 0.62.

2. After asking tough mathematical questions: RI=0.67, 0.70.

3. After giving a brief time for relaxation: RI=0.62, 0.62.

4. During and after asking a more difficult mathematical question:RI=0.71.

5. The person was relaxed with some humorous talk: RI=0.71.

6. After asking simple arithmetic questions: RI=0.67, 0.56, 0.63, 0.47.

7. After asking stressful personal question by physician: RI=0.64, 0.69,0.64, 0.66.

8. After giving time for relaxation: RI=0.59, 0.54.

9. After asking difficult arithmetic questions: RI=0.72, 0.63, 0.62,0.65, 0.67, 0.66, 0.65.

10. Return to baseline measurement (normal state): RI=0.57.

The patient was subjected to most of the same stressors as the patientin experiment 2. Initially the patient reported that he was stressed dueto the anxiety of the trial. The patients RI increased only slightlywhen he was asked mathematical questions. The patient answered many ofthe questions incorrectly. After the measurements, the patient was askedabout how he was feeling during the trial and what were the instanceswhen he felt stressed. The patient reported that the difficultmathematical questions were not stressful, though he stated that hetried his best to answer them.

When the patient was asked personal questions (state 7), his RIincreased. The patient reported that the personal questions werestressful, especially in the beginning of that phase of questions. Thisconfirmed that the personal questions stressed the patient. Though thepatient's RI increased, the increase in RI was slight, in an absolutesense, compared to the initial values. This suggests that the analysisof stress should be based on a comparison of local values (i.e., bycomparing the stressed state with the states immediately before andafter the stressed state).

The patient's baseline stress consistently declined during the course ofthe experiment (see states 1, 3, 8, and 10), indicating that the patientwas become more relaxed as the trial proceeded and as he became morecomfortable and familiar with the process.

Summary: Renal Doppler measurements were taken on the main renal artery.The patient did not need to hold his breath. Peaks and troughs wereselected automatically, and RI was also calculated automatically. Thepatient's subjective stress experience and feedback about the experimentwere recorded. Changes in RI correlated with the patient's self-reportedstress level, such that RI increased with stress.

State Average RI Inference Normal 0.61 Initial state; some anxiety oftrial Relaxed 0.57 RI decreased Mathematical Questions 0.69 Increased RIindicates stress Difficult Math Questions 0.66 RI decreased PersonalQuestions 0.66 Local RI increase is high

Conclusions from Examples 1-3

The hypothesis for these experiments was that would RI increase withstress and decrease with relaxation. This hypothesis was generallyconfirmed. In most cases it was observed that increasing RI correlatedwith increasing self-reported stress. However, in some cases RIdecreased when the patient was subjected to forced stress. Similarly, insome cases RI increased when the patient was subjected to forcedrelaxation. It is likely that in these latter cases, the forcedstress/relaxation was merely ineffective as inducing the expectedresponse. For example, in experiment 1 the patient actually became morerelaxed when asked arithmetic questions that were intended to inducestress, while asking the same patient to relax was ineffective atreducing his RI. This is likely because when the patient in experiment 1began the trial in a stressed state, such that his normal (baseline)stated was substantially stressed. Consequently, the forced relaxationmethod using talking and jokes was not enough to bring the patient outof the initial stressed state.

Asking mathematical questions was effective at inducing stress incertain situation. A question that was relatively difficult for thepatient to answer induced stress and an increase in RI was observed.However, a question that was relatively easy for the patient actuallyreduced the patient's stress and a decrease in RI was observed. Askingpersonal questions was also effective at inducing stress in patients,and the changes in RI caused by personal questions tended to be largerthan the changes caused by mathematical question. Consequently, changesin RI correlated with the difficult of the question asked, such that RIincreased with the difficulty of the question. Similarly, it wasobserved that more difficult questions had a larger (more positive)stress factor, such that the change in RI increased with the difficultyof the question.

It was also observed that the patients recovered from particularstressors relatively quickly, indicating that the patients hadfast-acting compensatory mechanisms for dealing with stress induced bymathematical and personal questions. Similarly, it indicates thatmathematical and personal questions are only capable of inducingshort-term stress responses. This also indicates that renal Dopplermeasurements should be taken continuously when asking these types ofquestions in order to increase the accuracy of the measurements.

Factors that may decrease the accuracy of Doppler measurements include:(1) physical motion of the person, especially breathing when takingmeasurements on intra-renal artery; (2) having the patient hold hisbreath, which may itself be stressful; (3) variations in the Dopplermeasurement angle between measurements; (4) manual selection of peaks introughs in Doppler waveforms, which may be dependent on the accuracy andexperience of the operating technician; or (5) delays between the timestress is induced and when a measurement is taken, which may cause asmaller change in RI to be observed because of fast-acting compensatorymechanisms. These factors may have affected the measurements inexperiment 1. However, these factors were effectively eliminated inexperiments 2 and 3 using the following techniques: (1) minimizing theeffect of physical motion, particularly breathing, by takingmeasurements on the main renal artery; (2) allowing the patient tobreath normally while taking measurements; (3) using equipment that canautomatically select the peaks and troughs in Doppler waveforms; and (5)taking measurements continuously. Consequently, the results ofexperiments 2 and 3 are likely more accurate than the results ofexperiment 1. However, the results of all three experiments support thehypothesis that RI increases with stress and decreases with relaxation.

In experiments 2 and 3, it was observed that the RI of a patientincreased significantly just before each question was asked. Thisreflected the patient's anxiety over the pending question. After thequestion was completed, RI remained elevated for difficult questionswhile the patient attempted to solve the question. However, for easyquestions, RI quickly decreased after the question was completed. Theshape of the Doppler waveform clearly changed when questions were asked,making it simple to identify and distinguish stressed and relaxedstated. Interestingly, it was observed that RI increased the most when apatient was asked to self-induce stress. RI decreased the most when apatient was asked to relax by using deep-breathing techniques, thusvalidating deep-breathing as an effective stress-reduction therapy.However, merely asking a patient to relax may not decrease their RI, andmay in fact cause an increase in RI.

While asking difficult questions generally increased a patient's stress,it was observed that asking questions that were too hard (i.e., beyondthe patient's ability to answer correctly) did not cause stress. Thismay be because the patient realizes his inability to answer the questionand gives up trying to solve the question, thereby avoiding a stressresponse. In experiment 3, the patient was initially stressed when askeddifficult mathematical question, but his RI quickly dropped after thefirst question as the patient effectively gave up trying to solve thequestions correctly. This correlated with the patient's report that hedid not feel stressed when asked difficult mathematical questions thathe generally could not solve.

Renal Doppler sonography provides a fast and reliable way to detectstress. However, the stress causing methodology is not normalized.Different patients reacted differently to the same type of questions.Thus the questionnaire should be prepared based on the particularpatient. For example, mathematical questions should be scaled based onthe patients education level. A common method of solving some mentalquestions works differently on different persons. The normal (baseline)state of patient also has a significant impact on their stress response.

In conclusion, renal Doppler sonography may be used to accuratelymeasure stress in a person. There is a strong correlation between apatient's RI and a patient's self-reported stress level. Therelationship between RI and stress may be used to generate and validatealgorithms used for calculating a stress index and stress factors.Furthermore, RI and self-reported stress data can be combined with datafrom other sensors to generate a stress model of the patient thatcorrelates a variety of physiological, psychological, behavioral, orenvironmental data of the patient with the stress or RI of the patient.

Example 4

In this experiment, physiological, psychological, behavioral, andenvironmental data is collected from multiple subjects. The subjectsconduct their daily activities normally while various sensorscontinuously monitor them. The patients wear a blood-pressure monitor,an actigraph, a pulse oximeter, the iPod Touch described above, and adata aggregation system. All of these are portable devices that thesubjects can carry. Also, periodically the subject's renal bloodvelocity, blood glucose level, and cortisol level is measured. Thesubjects can report psychological and behavioral data using an iPodTouch application, similar to mood sensor 400. The iPod Touch also hascustom software to verify the operation of the sensors and the dataaggregation system. During the experimental period, the subject isexposed to stress therapies (e.g., stress management and counseling).

Data is collected from ten normotensive subjects for at least four hoursa day over the course of two weeks (10 working days). Of the four hoursof data collection, approximately two hours of data will be collectedwhile the subject is at work and two hours of data will be collectedafter work. During the first week of data collection, the patient onlyengages in light relaxation during the two-hour post-work period eachday. During the second week of data collection the patient engaged instress management counseling during the post-work period each day.

The data is used to develop a stress model for each patient. The stressmodel correlates the physiological, psychological, behavioral, andenvironmental data collected during the experiment with the stress or RIof the subject. The renal Doppler measurements for a patient are used todetermine the stress index of the patient. The stress index is thencorrelated with the physiological, psychological, behavioral, andenvironmental data collected during the experiment. A stress model forcalculating the stress index of a person as a function of with thephysiological, psychological, behavioral, and environmental data is thendetermined. Thus, the renal Doppler measurements are effectively used tovalidate the stress model of the person.

Display

Display system 190 may render, visualize, display, message, and publishto one or more users based on the one or more analysis outputs fromanalysis system 180. In particular embodiments, one or more subjects ofone or more sensors 112 may be a user of display system 190. An analysisoutput from analysis system 180 may be transmitted to display system 190over any suitable medium. Display system 190 may include any suitableI/O device that can enable communication between a person and displaysystem 190. As an example and not by way of limitation, display system190 may include a video monitor, speaker, touch screen, printer, anothersuitable I/O device or a combination of two or more of these. Displaysystem 190 may be any computing device with a suitable I/O device, suchas computer system 1600.

In particular embodiments, display system 190 may comprise one or morelocal display systems 130 or one or more remote display systems 140.Where display system 190 comprises multiple subsystems (e.g., localdisplay systems 130 and remote display systems 140), display of analysisoutputs may occur on one or more subsystems. As an example and not byway of limitation, local display systems 130 and remote display systems140 may present identical displays based on the analysis output. Asanother example and not by way of limitation, local display systems 130and remote display systems 140 may present different displays based onthe analysis output. In particular embodiments, a user-input sensor insensor array 110 may also function as display system 190. Any clientsystem with a suitable I/O device may serve as a user-input sensor anddisplay system 190. As an example and not by way of limitation, a smartphone with a touch screen may function both as a user-input sensor andas display system 190.

In particular embodiments, display system 190 may display an analysisoutput in real-time as it is received from analysis system 180. Invarious embodiments, real-time analysis of data streams from sensorarray 110 by analysis system 180 allows a user to receive real-timeinformation about the health status of a subject. It is also possiblefor the user to receive real-time feedback from display system 190(e.g., warnings about health risks, recommending therapies, etc.).

Although this disclosure describes a display system 190 performingparticular display-related processes using particular techniques, thisdisclosure contemplates a display system 190 performing any suitabledisplay-related processes using any suitable techniques.

In particular embodiments, display system 190 may render and visualizedata based on analysis output from analysis system 180. Display system190 may render and visualize using any suitable means, includingcomputer system 1400 with a suitable I/O device, such as a videomonitor, speaker, touch screen, printer, another suitable I/O device ora combination of two or more of these.

Rendering is the process of generating an image from a model. The modelis a description of an object in a defined language or data structure.The description may contain color, size, orientation, geometry,viewpoint, texture, lighting, shading, and other object information. Therendering may be any suitable image, such as a digital image or rastergraphics image. Rendering may be performed on any suitable computingdevice.

Visualization is the process of creating images, diagrams, or animationsto communicate information to a user. Visualizations may includediagrams, images, objects, graphs, charts, lists, maps, text, etc.Visualization may be performed on any suitable device that may presentinformation to a user, including a video monitor, speaker, touch screen,printer, another suitable I/O device or a combination of two or more ofthese.

In some embodiments, rendering may be performed partially on analysissystem 180 and partially on display system 190. In other embodiments,rendering is completely performed on analysis system 180, whilevisualization is performed on display system 190.

In particular embodiments, display system 190 may message and publishdata based on analysis output from analysis system 180. Display system190 may message and publish using any suitable means, including email,instant message, text message, audio message, page, MMS text, socialnetwork message, another suitable messaging or publishing means, or acombination of two or more of these.

In particular embodiments, display system 190 may publish some or all ofthe analysis output such that the publication may be viewed by one ormore third-parties. In one embodiment, display system 190 mayautomatically publish the analysis output to one or more websites. As anexample and not by way of limitation, a subject of a GPS sensor (suchas, for example, a smart phone) may automatically have his locationpublished to a social networking site (such as, for example, Facebook,Twitter, or Foursquare).

In particular embodiments, display system 190 may send or message someor all of the analysis output to one or more third-parties. In oneembodiment, display system 190 may automatically send the analysisoutput to one or more healthcare providers. As an example and not by wayof limitation, a subject wearing a portable blood glucose monitor mayhave all of the data from that sensor transmitted to his doctor. Inanother embodiment, display system 190 will only send the analysisoutput to a healthcare provider when one or more threshold criteria aremet. As an example and not by way of limitation, a subject wearing aportable blood glucose monitor may not have any data from that sensortransmitted to his doctor unless his blood glucose data shows that he isseverely hypoglycemic (e.g., below 2.8 mmol/l). In particularembodiments, display system 190 may message one or more alerts to a useror third-party based on the analysis output. An alert may contain anotice, warning, or recommendation for the user or third-party. As anexample and not by way of limitation, a subject wearing a blood glucosemonitor may receive an alert if his blood glucose level shows that he ismoderately hypoglycemic (e.g., below 3.5 mmol/l) warning of thehypoglycemia and recommending that he eat something.

In particular embodiments, display system 190 may display one or moretherapies to a user based on analysis output from analysis system 180. Atherapy may be a recommended therapy for the user or a therapeuticfeedback that provide a direct therapeutic benefit to the user. Displaysystem 190 may deliver a variety of therapies, such as interventions,biofeedback, breathing exercises, progressive muscle relaxationexercises, presentation of personal media (e.g., music, personalpictures, etc.), offering an exit strategy (e.g., calling the user so hehas an excuse to leave a stressful situation), references to a range ofpsychotherapeutic techniques, and graphical representations of trends(e.g., illustrations of health metrics over time), cognitive reframingtherapy, and other therapeutic feedbacks. Although this disclosuredescribes display system 190 delivering particular therapies, thisdisclosure contemplates display system 190 delivering any suitabletherapies.

Systems and Methods

FIG. 16 illustrates an example computer system 1600. In particularembodiments, one or more computer systems 1600 perform one or more stepsof one or more methods described or illustrated herein. In particularembodiments, one or more computer systems 1600 provide functionalitydescribed or illustrated herein. In particular embodiments, softwarerunning on one or more computer systems 1600 performs one or more stepsof one or more methods described or illustrated herein or providesfunctionality described or illustrated herein. Particular embodimentsinclude one or more portions of one or more computer systems 1600.

This disclosure contemplates any suitable number of computer systems1600. This disclosure contemplates computer system 1600 taking anysuitable physical form. As example and not by way of limitation,computer system 1600 may be an embedded computer system, asystem-on-chip (SOC), a single-board computer system (SBC) (such as, forexample, a computer-on-module (COM) or system-on-module (SOM)), adesktop computer system, a laptop or notebook computer system, aninteractive kiosk, a mainframe, a mesh of computer systems, a mobiletelephone, a personal digital assistant (PDA), a server, a tabletcomputer system, or a combination of two or more of these. Whereappropriate, computer system 1600 may include one or more computersystems 1600; be unitary or distributed; span multiple locations; spanmultiple machines; span multiple data centers; or reside in a cloud,which may include one or more cloud components in one or more networks.Where appropriate, one or more computer systems 1600 may perform withoutsubstantial spatial or temporal limitation one or more steps of one ormore methods described or illustrated herein. As an example and not byway of limitation, one or more computer systems 1600 may perform in realtime or in batch mode one or more steps of one or more methods describedor illustrated herein. One or more computer systems 1600 may perform atdifferent times or at different locations one or more steps of one ormore methods described or illustrated herein, where appropriate.

In particular embodiments, computer system 1600 includes a processor1602, memory 1604, storage 1606, an input/output (I/O) interface 1608, acommunication interface 1610, and a bus 1612. Although this disclosuredescribes and illustrates a particular computer system having aparticular number of particular components in a particular arrangement,this disclosure contemplates any suitable computer system having anysuitable number of any suitable components in any suitable arrangement.

In particular embodiments, processor 1602 includes hardware forexecuting instructions, such as those making up a computer program. Asan example and not by way of limitation, to execute instructions,processor 1602 may retrieve (or fetch) the instructions from an internalregister, an internal cache, memory 1604, or storage 1606; decode andexecute them; and then write one or more results to an internalregister, an internal cache, memory 1604, or storage 1606. In particularembodiments, processor 1602 may include one or more internal caches fordata, instructions, or addresses. This disclosure contemplates processor1602 including any suitable number of any suitable internal caches,where appropriate. As an example and not by way of limitation, processor1602 may include one or more instruction caches, one or more datacaches, and one or more translation lookaside buffers (TLBs).Instructions in the instruction caches may be copies of instructions inmemory 1604 or storage 1606, and the instruction caches may speed upretrieval of those instructions by processor 1602. Data in the datacaches may be copies of data in memory 1604 or storage 1606 forinstructions executing at processor 1602 to operate on; the results ofprevious instructions executed at processor 1602 for access bysubsequent instructions executing at processor 1602 or for writing tomemory 1604 or storage 1606; or other suitable data. The data caches mayspeed up read or write operations by processor 1602. The TLBs may speedup virtual-address translation for processor 1602. In particularembodiments, processor 1602 may include one or more internal registersfor data, instructions, or addresses. This disclosure contemplatesprocessor 1602 including any suitable number of any suitable internalregisters, where appropriate. Where appropriate, processor 1602 mayinclude one or more arithmetic logic units (ALUs); be a multi-coreprocessor; or include one or more processors 1602. Although thisdisclosure describes and illustrates a particular processor, thisdisclosure contemplates any suitable processor.

In particular embodiments, memory 1604 includes main memory for storinginstructions for processor 1602 to execute or data for processor 1602 tooperate on. As an example and not by way of limitation, computer system1600 may load instructions from storage 1606 or another source (such as,for example, another computer system 1600) to memory 1604. Processor1602 may then load the instructions from memory 1604 to an internalregister or internal cache. To execute the instructions, processor 1602may retrieve the instructions from the internal register or internalcache and decode them. During or after execution of the instructions,processor 1602 may write one or more results (which may be intermediateor final results) to the internal register or internal cache. Processor1602 may then write one or more of those results to memory 1604. Inparticular embodiments, processor 1602 executes only instructions in oneor more internal registers or internal caches or in memory 1604 (asopposed to storage 1606 or elsewhere) and operates only on data in oneor more internal registers or internal caches or in memory 1604 (asopposed to storage 1606 or elsewhere). One or more memory buses (whichmay each include an address bus and a data bus) may couple processor1602 to memory 1604. Bus 1612 may include one or more memory buses, asdescribed below. In particular embodiments, one or more memorymanagement units (MMUs) reside between processor 1602 and memory 1604and facilitate accesses to memory 1604 requested by processor 1602. Inparticular embodiments, memory 1604 includes random access memory (RAM).This RAM may be volatile memory, where appropriate Where appropriate,this RAM may be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, whereappropriate, this RAM may be single-ported or multi-ported RAM. Thisdisclosure contemplates any suitable RAM. Memory 1604 may include one ormore memories 1604, where appropriate. Although this disclosuredescribes and illustrates particular memory, this disclosurecontemplates any suitable memory.

In particular embodiments, storage 1606 includes mass storage for dataor instructions. As an example and not by way of limitation, storage1606 may include an HDD, a floppy disk drive, flash memory, an opticaldisc, a magneto-optical disc, magnetic tape, or a Universal Serial Bus(USB) drive or a combination of two or more of these. Storage 1606 mayinclude removable or non-removable (or fixed) media, where appropriate.Storage 1606 may be internal or external to computer system 1600, whereappropriate. In particular embodiments, storage 1606 is non-volatile,solid-state memory. In particular embodiments, storage 1606 includesread-only memory (ROM). Where appropriate, this ROM may bemask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM),electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM),or flash memory or a combination of two or more of these. Thisdisclosure contemplates mass storage 1606 taking any suitable physicalform. Storage 1606 may include one or more storage control unitsfacilitating communication between processor 1602 and storage 1606,where appropriate. Where appropriate, storage 1606 may include one ormore storages 1606. Although this disclosure describes and illustratesparticular storage, this disclosure contemplates any suitable storage.

In particular embodiments, I/O interface 1608 includes hardware,software, or both providing one or more interfaces for communicationbetween computer system 1600 and one or more I/O devices. Computersystem 1600 may include one or more of these I/O devices, whereappropriate. One or more of these I/O devices may enable communicationbetween a person and computer system 1600. As an example and not by wayof limitation, an I/O device may include a keyboard, keypad, microphone,monitor, mouse, printer, scanner, speaker, still camera, stylus, tablet,touch screen, trackball, video camera, another suitable I/O device or acombination of two or more of these. An I/O device may include one ormore sensors. This disclosure contemplates any suitable I/O devices andany suitable I/O interfaces 1608 for them. Where appropriate, I/Ointerface 1608 may include one or more device or software driversenabling processor 1602 to drive one or more of these I/O devices. I/Ointerface 1608 may include one or more I/O interfaces 1608, whereappropriate. Although this disclosure describes and illustrates aparticular I/O interface, this disclosure contemplates any suitable I/Ointerface.

In particular embodiments, communication interface 1610 includeshardware, software, or both providing one or more interfaces forcommunication (such as, for example, packet-based communication) betweencomputer system 1600 and one or more other computer systems 1600 or oneor more networks. As an example and not by way of limitation,communication interface 1610 may include a network interface controller(NIC) or network adapter for communicating with an Ethernet or otherwire-based network or a wireless NIC (WNIC) or wireless adapter forcommunicating with a wireless network, such as a WI-FI network. Thisdisclosure contemplates any suitable network and any suitablecommunication interface 1610 for it. As an example and not by way oflimitation, computer system 1600 may communicate with an ad hoc network,a personal area network (PAN), a local area network (LAN), a wide areanetwork (WAN), a metropolitan area network (MAN), or one or moreportions of the Internet or a combination of two or more of these. Oneor more portions of one or more of these networks may be wired orwireless. As an example, computer system 1600 may communicate with awireless PAN (WPAN) (such as, for example, a BLUETOOTH WPAN), a WI-FInetwork, a WI-MAX network, a cellular telephone network (such as, forexample, a Global System for Mobile Communications (GSM) network), orother suitable wireless network or a combination of two or more ofthese. Computer system 1600 may include any suitable communicationinterface 1610 for any of these networks, where appropriate.Communication interface 1610 may include one or more communicationinterfaces 1610, where appropriate. Although this disclosure describesand illustrates a particular communication interface, this disclosurecontemplates any suitable communication interface.

In particular embodiments, bus 1612 includes hardware, software, or bothcoupling components of computer system 1600 to each other. As an exampleand not by way of limitation, bus 1612 may include an AcceleratedGraphics Port (AGP) or other graphics bus, an Enhanced Industry StandardArchitecture (EISA) bus, a front-side bus (FSB), a HYPERTRANSPORT (HT)interconnect, an Industry Standard Architecture (ISA) bus, an INFINIBANDinterconnect, a low-pin-count (LPC) bus, a memory bus, a Micro ChannelArchitecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, aPCI-Express (PCI-X) bus, a serial advanced technology attachment (SATA)bus, a Video Electronics Standards Association local (VLB) bus, oranother suitable bus or a combination of two or more of these. Bus 1612may include one or more buses 1612, where appropriate. Although thisdisclosure describes and illustrates a particular bus, this disclosurecontemplates any suitable bus or interconnect.

Herein, reference to a computer-readable storage medium encompasses oneor more non-transitory, tangible computer-readable storage mediapossessing structure. As an example and not by way of limitation, acomputer-readable storage medium may include a semiconductor-based orother integrated circuit (IC) (such, as for example, afield-programmable gate array (FPGA) or an application-specific IC(ASIC)), a hard disk, an HDD, a hybrid hard drive (HHD), an opticaldisc, an optical disc drive (ODD), a magneto-optical disc, amagneto-optical drive, a floppy disk, a floppy disk drive (FDD),magnetic tape, a holographic storage medium, a solid-state drive (SSD),a RAM-drive, a SECURE DIGITAL card, a SECURE DIGITAL drive, or anothersuitable computer-readable storage medium or a combination of two ormore of these, where appropriate. Herein, reference to acomputer-readable storage medium excludes any medium that is noteligible for patent protection under 35 U.S.C. §101. Herein, referenceto a computer-readable storage medium excludes transitory forms ofsignal transmission (such as a propagating electrical or electromagneticsignal per se) to the extent that they are not eligible for patentprotection under 35 U.S.C. §101. A computer-readable non-transitorystorage medium may be volatile, non-volatile, or a combination ofvolatile and non-volatile, where appropriate.

This disclosure contemplates one or more computer-readable storage mediaimplementing any suitable storage. In particular embodiments, acomputer-readable storage medium implements one or more portions ofprocessor 1602 (such as, for example, one or more internal registers orcaches), one or more portions of memory 1604, one or more portions ofstorage 1606, or a combination of these, where appropriate. Inparticular embodiments, a computer-readable storage medium implementsRAM or ROM. In particular embodiments, a computer-readable storagemedium implements volatile or persistent memory. In particularembodiments, one or more computer-readable storage media embodysoftware. Herein, reference to software may encompass one or moreapplications, bytecode, one or more computer programs, one or moreexecutables, one or more instructions, logic, machine code, one or morescripts, or source code, and vice versa, where appropriate. Inparticular embodiments, software includes one or more applicationprogramming interfaces (APIs). This disclosure contemplates any suitablesoftware written or otherwise expressed in any suitable programminglanguage or combination of programming languages. In particularembodiments, software is expressed as source code or object code. Inparticular embodiments, software is expressed in a higher-levelprogramming language, such as, for example, C, Perl, or a suitableextension thereof. In particular embodiments, software is expressed in alower-level programming language, such as assembly language (or machinecode). In particular embodiments, software is expressed in JAVA. Inparticular embodiments, software is expressed in Hyper Text MarkupLanguage (HTML), Extensible Markup Language (XML), or other suitablemarkup language.

FIG. 17 illustrates an example network environment 1700. This disclosurecontemplates any suitable network environment 1700. As an example andnot by way of limitation, although this disclosure describes andillustrates a network environment 1700 that implements a client-servermodel, this disclosure contemplates one or more portions of a networkenvironment 1700 being peer-to-peer, where appropriate. Particularembodiments may operate in whole or in part in one or more networkenvironments 1700. In particular embodiments, one or more elements ofnetwork environment 1700 provide functionality described or illustratedherein. Particular embodiments include one or more portions of networkenvironment 1700. Network environment 1700 includes a network 1710coupling one or more servers 1720 and one or more clients 1730 to eachother. This disclosure contemplates any suitable network 1710. As anexample and not by way of limitation, one or more portions of network1710 may include an ad hoc network, an intranet, an extranet, a virtualprivate network (VPN), a local area network (LAN), a wireless LAN(WLAN), a wide area network (WAN), a wireless WAN (WWAN), a metropolitanarea network (MAN), a portion of the Internet, a portion of the PublicSwitched Telephone Network (PSTN), a cellular telephone network, or acombination of two or more of these. Network 1710 may include one ormore networks 1710.

Links 1750 couple servers 1720 and clients 1730 to network 1710 or toeach other. This disclsoure contemplates any suitable links 1750. As anexample and not by way of limitation, one or more links 1750 eachinclude one or more wireline (such as, for example, Digital SubscriberLine (DSL) or Data Over Cable Service Interface Specification (DOCSIS)),wireless (such as, for example, Wi-Fi or Worldwide Interoperability forMicrowave Access (WiMAX)) or optical (such as, for example, SynchronousOptical Network (SONET) or Synchronous Digital Hierarchy (SDH)) links1750. In particular embodiments, one or more links 1750 each includes anintranet, an extranet, a VPN, a LAN, a WLAN, a WAN, a MAN, acommunications network, a satellite network, a portion of the Internet,or another link 1750 or a combination of two or more such links 1750.Links 1750 need not necessarily be the same throughout networkenvironment 1700. One or more first links 1750 may differ in one or morerespects from one or more second links 1750.

This disclosure contemplates any suitable servers 1720. As an exampleand not by way of limitation, one or more servers 1720 may each includeone or more advertising servers, applications servers, catalog servers,communications servers, database servers, exchange servers, fax servers,file servers, game servers, home servers, mail servers, message servers,news servers, name or DNS servers, print servers, proxy servers, soundservers, standalone servers, web servers, or web-feed servers. Inparticular embodiments, a server 1720 includes hardware, software, orboth for providing the functionality of server 1720. As an example andnot by way of limitation, a server 1720 that operates as a web servermay be capable of hosting websites containing web pages or elements ofweb pages and include appropriate hardware, software, or both for doingso. In particular embodiments, a web server may host HTML or othersuitable files or dynamically create or constitute files for web pageson request. In response to a Hyper Text Transfer Protocol (HTTP) orother request from a client 1730, the web server may communicate one ormore such files to client 1730. As another example, a server 1720 thatoperates as a mail server may be capable of providing e-mail services toone or more clients 1730. As another example, a server 1720 thatoperates as a database server may be capable of providing an interfacefor interacting with one or more data stores (such as, for example, datastores 1740 described below). Where appropriate, a server 1720 mayinclude one or more servers 1720; be unitary or distributed; spanmultiple locations; span multiple machines; span multiple datacenters;or reside in a cloud, which may include one or more cloud components inone or more networks.

In particular embodiments, one or more links 1750 may couple a server1720 to one or more data stores 1740. A data store 1740 may store anysuitable information, and the contents of a data store 1740 may beorganized in any suitable manner. As an example and not by way orlimitation, the contents of a data store 1740 may be stored as adimensional, flat, hierarchical, network, object-oriented, relational,XML, or other suitable database or a combination or two or more ofthese. A data store 1740 (or a server 1720 coupled to it) may include adatabase-management system or other hardware or software for managingthe contents of data store 1740. The database-management system mayperform read and write operations, delete or erase data, perform datadeduplication, query or search the contents of data store 1740, orprovide other access to data store 1740.

In particular embodiments, one or more servers 1720 may each include oneor more search engines 1722. A search engine 1722 may include hardware,software, or both for providing the functionality of search engine 1722.As an example and not by way of limitation, a search engine 1722 mayimplement one or more search algorithms to identify network resources inresponse to search queries received at search engine 1722, one or moreranking algorithms to rank identified network resources, or one or moresummarization algorithms to summarize identified network resources. Inparticular embodiments, a ranking algorithm implemented by a searchengine 1722 may use a machine-learned ranking formula, which the rankingalgorithm may obtain automatically from a set of training dataconstructed from pairs of search queries and selected Uniform ResourceLocators (URLs), where appropriate.

In particular embodiments, one or more servers 1720 may each include oneor more data monitors/collectors 1724. A data monitor/collection 1724may include hardware, software, or both for providing the functionalityof data collector/collector 1724. As an example and not by way oflimitation, a data monitor/collector 1724 at a server 1720 may monitorand collect network-traffic data at server 1720 and store thenetwork-traffic data in one or more data stores 1740. In particularembodiments, server 1720 or another device may extract pairs of searchqueries and selected URLs from the network-traffic data, whereappropriate.

This disclosure contemplates any suitable clients 1730. A client 1730may enable a user at client 1730 to access or otherwise communicate withnetwork 1710, servers 1720, or other clients 1730. As an example and notby way of limitation, a client 1730 may have a web browser, such asMICROSOFT INTERNET EXPLORER or MOZILLA FIREFOX, and may have one or moreadd-ons, plug-ins, or other extensions, such as GOOGLE TOOLBAR or YAHOOTOOLBAR. A client 1730 may be an electronic device including hardware,software, or both for providing the functionality of client 1730. As anexample and not by way of limitation, a client 1730 may, whereappropriate, be an embedded computer system, an SOC, an SBC (such as,for example, a COM or SOM), a desktop computer system, a laptop ornotebook computer system, an interactive kiosk, a mainframe, a mesh ofcomputer systems, a mobile telephone, a PDA, a netbook computer system,a server, a tablet computer system, or a combination of two or more ofthese. Where appropriate, a client 1730 may include one or more clients1730; be unitary or distributed; span multiple locations; span multiplemachines; span multiple datacenters; or reside in a cloud, which mayinclude one or more cloud components in one or more networks.

Miscellaneous

Herein, “or” is inclusive and not exclusive, unless expressly indicatedotherwise or indicated otherwise by context. Therefore, herein, “A or B”means “A, B, or both,” unless expressly indicated otherwise or indicatedotherwise by context. Moreover, “and” is both joint and several, unlessexpressly indicated otherwise or indicated otherwise by context.Therefore, herein, “A and B” means “A and B, jointly or severally,”unless expressly indicated otherwise or indicated otherwise by context.Furthermore, “a”, “an,” or “the” is intended to mean “one or more,”unless expressly indicated otherwise or indicated otherwise by context.Therefore, herein, “an A” or “the A” means “one or more A,” unlessexpressly indicated otherwise or indicated otherwise by context.

This disclosure encompasses all changes, substitutions, variations,alterations, and modifications to the example embodiments herein that aperson having ordinary skill in the art would comprehend. Similarly,where appropriate, the appended claims encompass all changes,substitutions, variations, alterations, and modifications to the exampleembodiments herein that a person having ordinary skill in the art wouldcomprehend. Moreover, this disclosure encompasses any suitablecombination of one or more features from any example embodiment with oneor more features of any other example embodiment herein that a personhaving ordinary skill in the art would comprehend. Furthermore,reference in the appended claims to an apparatus or system or acomponent of an apparatus or system being adapted to, arranged to,capable of, configured to, enabled to, operable to, or operative toperform a particular function encompasses that apparatus, system,component, whether or not it or that particular function is activated,turned on, or unlocked, as long as that apparatus, system, or componentis so adapted, arranged, capable, configured, enabled, operable, oroperative.

REFERENCES

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All patent and literature references cite herein are incorporated byreference as if fully set forth.

What is claimed is:
 1. A method comprising, by one or more processorsassociated with one or more computing devices: accessing, by one or moreof the processors, one or more data streams from a plurality of sensors,wherein: the sensors comprise: a glucocorticoid meter and one or morefirst sensors selected from a first group of sensor types consisting ofa heart-rate monitor, a blood-pressure monitor, a pulse oximeter, and anaccelerometer; one or two second sensors selected from a second group ofsensor types consisting of a mood sensor, a behavioral sensor, and anenvironmental sensor; one third sensor also selected from the secondgroup of sensor types, the third sensor being different in sensor typefrom each of the two second sensors; the data streams compriseglucocorticoid data of a person from the glucocorticoid meter and one ormore of heart-rate data of the person from the heart-rate monitor,blood-pressure data of the person from the blood-pressure monitor,pulse-oximetry data of the person from the pulse oximeter, accelerometerdata of the person from the accelerometer, self-reported mood data ofthe person from the mood sensor, behavioral data of the person from thebehavioral sensor, or environmental data from the environmental sensor;a first data set from the data streams was collected from the person ata first time, the person having been exposed to a stressor at the firsttime, as indicated by data in the first data set from the glucocorticoidmeter and the third sensor; and a second data set from the data streamswas collected from the person at a second time, the person not havingbeen exposed to the stressor at the second time, as indicated by data inthe second data set from the glucocorticoid meter and the third sensor;accessing, by one or more of the processors, a stress model comprisingbaseline renal-Doppler data and baseline glucocorticoid data of theperson, and two or more of baseline heart-rate data of the person,baseline blood-pressure data of the person, baseline pulse-oximetry dataof the person, baseline accelerometer data of the person, or baselineself-reported mood data of the person, wherein thebaseline-renal-Doppler data measures a stress response of thesympathetic nervous system, and wherein the stress model correlates thebaseline renal-Doppler data and the baseline glucocorticoid data of theperson with the baseline heart-rate data of the person, the baselineblood-pressure data of the person, the baseline pulse-oximetry data ofthe person, the baseline accelerometer data of the person, or thebaseline self-reported mood data of the person; analyzing, by one ormore of the processors, the first data set and second data set withrespect to each other and with respect to the stress model; determining,by one or more of the processors, a current stress factor for thestressor with respect to the person based on the analysis of the firstdata set and second data set with respect to each other and with respectto the stress model; and transmitting, by one or more of the processors,a warning to a designated computing system referencing the currentstress factor if the current stress factor deviates from a set ofcontrol parameters.
 2. The method of claim 1, wherein the environmentalsensor is selected from a fourth group consisting of a barometer, aweather sensor, a pollen counter, a location sensor, a seismometer, analtimeter, a hydrometer, a decibel meter, a light meter, a thermometer,a wind sensor, and a traffic sensor.
 3. The method of claim 1, whereinthe environmental sensor is a data feed.
 4. The method of claim 1,determining the current stress factor for the stressor with respect tothe person based on the analysis of the first data set and second dataset with respect to each other comprises: determining a first stressindex of the person based on the first data set; determining a secondstress index of the person based on the second data set; and determininga current stress factor for the stressor with respect to the personbased on a comparison of the first stress index and second stress indexof the person with respect to each other.
 5. The method of claim 4,wherein the data from the second sensors is used to validate the stressindex of the person.
 6. The method of claim 1, wherein the data from thesecond sensors is used to validate the current stress factor of theperson.
 7. The method of claim 1, further comprising: accessing a priorstress factor for the stressor of the person that precedes the currentstress factor; analyzing the current stress factor and prior stressfactor for the stressor of the person with respect to each other; anddetermining whether there is a change in the stress factor for thestressor of the person based on the analysis of the current stressfactor and prior stress factor with respect to each other.
 8. The methodof claim 1, wherein one or more of the sensors from the first group isaffixed to the person's body.
 9. The method of claim 1, wherein thestress model comprises an algorithm that comprises a plurality ofvariables based on two or more of the heart-rate data of the person, theblood-pressure data of the person, the pulse-oximetry data of theperson, the accelerometer data of the person, or the self-reported mooddata of the person.
 10. The method of claim 1, wherein: at the firsttime the person was stressed; and at the second time the person wasunstressed.
 11. The method of claim 1, wherein: at the first time theperson was engaged in a first activity; and at the second time theperson was engaged in a second activity.
 12. The method of claim 1,wherein: the first group further consists of an electrocardiograph; andthe data streams further comprise electrocardiograph data of the personfrom the electrocardiograph.
 13. The method of claim 1, wherein: thefirst group further consists of an electromyograph; and the data streamsfurther comprise electromyograph data of the person from theelectromyograph.
 14. The method of claim 1, wherein: the first groupfurther consists of a respiration sensor; and the data streams furthercomprise respiration data of the person from the respiration sensor. 15.The method of claim 1, wherein: the first group further consists of agalvanic-skin-response sensor; and the data streams further comprisegalvanic-skin-response data of the person from thegalvanic-skin-response sensor.
 16. An apparatus comprising: one or moreprocessors; and a memory coupled to the processors comprisinginstructions executable by the processors, the processors operable whenexecuting the instructions to: access one or more data streams from aplurality of sensors, wherein: the sensors comprise: a glucocorticoidmeter and one or more first sensors selected from a first group ofsensor types consisting of a heart-rate monitor, a blood-pressuremonitor, a pulse oximeter, and an accelerometer; one or two secondsensors selected from a second group of sensor types consisting of amood sensor, a behavioral sensor, and an environmental sensor; one thirdsensor also selected from the second group of sensor types, the thirdsensor being different in sensor type from each of the two secondsensors; the data streams comprise glucocorticoid data of a person fromthe glucocorticoid meter and one or more of heart-rate data of theperson from the heart-rate monitor, blood-pressure data of the personfrom the blood-pressure monitor, pulse-oximetry data of the person fromthe pulse oximeter, accelerometer data of the person from theaccelerometer, self-reported mood data of the person from the moodsensor, behavioral data of the person from the behavioral sensor, orenvironmental data from the environmental sensor; a first data set fromthe data streams was collected from the person at a first time, theperson having been exposed to a stressor at the first time, as indicatedby data in the first data set from the glucocorticoid meter and thethird sensor; and a second data set from the data streams was collectedfrom the person at a second time, the person not having been exposed tothe stressor at the second time, as indicated by data in the second dataset from the glucocorticoid meter and the third sensor; access a stressmodel comprising baseline renal-Doppler data and baseline glucocorticoiddata of the person, and two or more of baseline heart-rate data of theperson, baseline blood-pressure data of the person, baselinepulse-oximetry data of the person, baseline accelerometer data of theperson, or baseline self-reported mood data of the person, wherein thebaseline-renal-Doppler data measures a stress response of thesympathetic nervous system, and wherein the stress model correlates thebaseline renal-Doppler data and the baseline glucocorticoid data of theperson with the baseline heart-rate data of the person, the baselineblood-pressure data of the person, the baseline pulse-oximetry data ofthe person, the baseline accelerometer data of the person, or thebaseline self-reported mood data of the person; analyze the first dataset and second data set with respect to each other and with respect tothe stress model; determine a current stress factor for the stressorwith respect to the person based on the analysis of the first data setand second data set with respect to each other and with respect to thestress model; and transmit a warning to a designated computing system ofthe person referencing the current stress factor if the current stressfactor deviates from a set of control parameters.
 17. The apparatus ofclaim 16, wherein the environmental sensor is selected from a fourthgroup consisting of a barometer, a weather sensor, a pollen counter, alocation sensor, a seismometer, an altimeter, a hydrometer, a decibelmeter, a light meter, a thermometer, a wind sensor, and a trafficsensor.
 18. The apparatus of claim 16, wherein the environmental sensoris a data feed.
 19. The apparatus of claim 16, wherein to determine thecurrent stress factor for the stressor with respect to the person basedon the analysis of the first data set and second data set with respectto each other comprises: to determine a first stress index of the personbased on the first data set; to determine a second stress index of theperson based on the second data set; and to determine a current stressfactor for the stressor with respect to the person based on a comparisonof the first stress index and second stress index of the person withrespect to each other.
 20. The apparatus of claim 19, wherein the datafrom the second sensors is used to validate the stress index of theperson.
 21. The apparatus of claim 16, wherein the data from the secondsensors is used to validate the current stress factor of the person. 22.The apparatus of claim 16, the apparatus further operable when executinginstructions to: access a prior stress factor for the stressor of theperson that precedes the current stress factor; analyze the currentstress factor and prior stress factor for the stressor of the personwith respect to each other; and determine whether there is a change inthe stress factor for the stressor of the person based on the analysisof the current stress factor and prior stress factor with respect toeach other.
 23. The apparatus of claim 16, wherein one or more of thesensors from the first group is affixed to the person's body.
 24. Theapparatus of claim 16, wherein the stress model comprises an algorithmthat comprises a plurality of variables based on two or more of theheart-rate data of the person, the blood-pressure data of the person,the pulse-oximetry data of the person, the accelerometer data of theperson, or the self-reported mood data of the person.
 25. The apparatusof claim 16, wherein: at the first time the person was stressed; and atthe second time the person was unstressed.
 26. The apparatus of claim16, wherein: at the first time the person was engaged in a firstactivity; and at the second time the person was engaged in a secondactivity.
 27. The apparatus of claim 16, wherein: the first groupfurther consists of an electrocardiograph; and the data streams furthercomprise electrocardiograph data of the person from theelectrocardiograph.
 28. The apparatus of claim 16, wherein: the firstgroup further consists of an electromyograph; and the data streamsfurther comprise electromyograph data of the person from theelectromyograph.
 29. The apparatus of claim 16, wherein: the first groupfurther consists of a respiration sensor; and the data streams furthercomprise respiration data of the person from the respiration sensor. 30.The apparatus of claim 16, wherein: the first group further consists ofa galvanic-skin-response sensor; and the data streams further comprisegalvanic-skin-response data of the person from thegalvanic-skin-response sensor.
 31. One or more computer-readablenon-transitory storage media embodying software that is operable whenexecuted to: access one or more data streams from a plurality ofsensors, wherein: the sensors comprise: a glucocorticoid meter and oneor more first sensors selected from a first group of sensor typesconsisting of a heart-rate monitor, a blood-pressure monitor, a pulseoximeter, and an accelerometer; one or two second sensors selected froma second group of sensor types consisting of a mood sensor, a behavioralsensor, and an environmental sensor; one third sensor also selected fromthe second group of sensor types, the third sensor being different insensor type from each of the two second sensors; the data streamscomprise glucocorticoid data of a person from the glucocorticoid meterand one or more of heart-rate data of the person from the heart-ratemonitor, blood-pressure data of the person from the blood-pressuremonitor, pulse-oximetry data of the person from the pulse oximeter,accelerometer data of the person from the accelerometer, self-reportedmood data of the person from the mood sensor, behavioral data of theperson from the behavioral sensor, or environmental data from theenvironmental sensor; a first data set from the data streams wascollected from the person at a first time, the person having beenexposed to a stressor at the first time, as indicated by data in thefirst data set from the glucocorticoid meter and the third sensor; and asecond data set from the data streams was collected from the person at asecond time, the person not having been exposed to the stressor at thesecond time, as indicated by data in the second data set from theglucocorticoid meter and the third sensor; access a stress modelcomprising baseline renal-Doppler data and baseline glucocorticoid dataof the person, and two or more of baseline heart-rate data of theperson, baseline blood-pressure data of the person, baselinepulse-oximetry data of the person, baseline accelerometer data of theperson, or baseline self-reported mood data of the person, wherein thebaseline-renal-Doppler data measures a stress response of thesympathetic nervous system, and wherein the stress model correlates thebaseline renal-Doppler data and the baseline glucocorticoid data of theperson with the baseline heart-rate data of the person, the baselineblood-pressure data of the person, the baseline pulse-oximetry data ofthe person, the baseline accelerometer data of the person, or thebaseline self-reported mood data of the person; analyze the first dataset and second data set with respect to each other and with respect tothe stress model; determine a current stress factor for the stressorwith respect to the person based on the analysis of the first data setand second data set with respect to each other and with respect to thestress model; and transmit a warning to a designated computing system ofthe person referencing the current stress factor if the current stressfactor deviates from a set of control parameters.
 32. The media of claim31, wherein the environmental sensor is selected from a fourth groupconsisting of a barometer, a weather sensor, a pollen counter, alocation sensor, a seismometer, an altimeter, a hydrometer, a decibelmeter, a light meter, a thermometer, a wind sensor, and a trafficsensor.
 33. The media of claim 31, wherein the environmental sensor is adata feed.
 34. The media of claim 31, wherein to determine the currentstress factor for the stressor with respect to the person based on theanalysis of the first data set and second data set with respect to eachother comprises: to determine a first stress index of the person basedon the first data set; to determine a second stress index of the personbased on the second data set; and to determine a current stress factorfor the stressor with respect to the person based on a comparison of thefirst stress index and second stress index of the person with respect toeach other.
 35. The media of claim 34, wherein the data from the secondsensors is used to validate the stress index of the person.
 36. Themedia of claim 31, wherein the data from the second sensors is used tovalidate the current stress factor of the person.
 37. The media of claim31, the media embodying instructions further operable when executed to:access a prior stress factor for the stressor of the person thatprecedes the current stress factor; analyze the current stress factorand prior stress factor for the stressor of the person with respect toeach other; and determine whether there is a change in the stress factorfor the stressor of the person based on the analysis of the currentstress factor and prior stress factor with respect to each other. 38.The media of claim 31, wherein one or more of the sensors from the firstgroup is affixed to the person's body.
 39. The media of claim 31,wherein the stress model comprises an algorithm that comprises aplurality of variables based on two or more of the heart-rate data ofthe person, the blood-pressure data of the person, the pulse-oximetrydata of the person, the accelerometer data of the person, or theself-reported mood data of the person.
 40. The media of claim 31,wherein: at the first time the person was stressed; and at the secondtime the person was unstressed.
 41. The media of claim 31, wherein: atthe first time the person was engaged in a first activity; and at thesecond time the person was engaged in a second activity.
 42. The mediaof claim 31, wherein: the first group further consists of anelectrocardiograph; and the data streams further compriseelectrocardiograph data of the person from the electrocardiograph. 43.The media of claim 31, wherein: the first group further consists of anelectromyograph; and the data streams further comprise electromyographdata of the person from the electromyograph.
 44. The media of claim 31,wherein: the first group further consists of a respiration sensor; andthe data streams further comprise respiration data of the person fromthe respiration sensor.
 45. The media of claim 31, wherein: the firstgroup further consists of a galvanic-skin-response sensor; and the datastreams further comprise galvanic-skin-response data of the person fromthe galvanic-skin-response sensor.
 46. A system comprising: means foraccessing one or more data streams from a plurality of sensors, wherein:the sensors comprise: a glucocorticoid meter and one or more firstsensors selected from a first group of sensor types consisting of aheart-rate monitor, a blood-pressure monitor, a pulse oximeter, and anaccelerometer; one or two second sensors selected from a second group ofsensor types consisting of a mood sensor, a behavioral sensor, and anenvironmental sensor; one third sensor also selected from the secondgroup of sensor types, the third sensor being different in sensor typefrom each of the two second sensors; the data streams compriseglucocorticoid data of a person from the glucocorticoid meter and one ormore of heart-rate data of the person from the heart-rate monitor,blood-pressure data of the person from the blood-pressure monitor,pulse-oximetry data of the person from the pulse oximeter, accelerometerdata of the person from the accelerometer, self-reported mood data ofthe person from the mood sensor, behavioral data of the person from thebehavioral sensor, or environmental data from the environmental sensor;a first data set from the data streams was collected from the person ata first time, the person having been exposed to a stressor at the firsttime, as indicated by data in the first data set from the glucocorticoidmeter and the third sensor; and a second data set from the data streamswas collected from the person at a second time, the person not havingbeen exposed to the stressor at the second time, as indicated by data inthe second data set from the glucocorticoid meter and the third sensor;means for accessing a stress model comprising baseline renal-Dopplerdata and baseline glucocorticoid data of the person, and two or more ofbaseline heart-rate data of the person, baseline blood-pressure data ofthe person, baseline pulse-oximetry data of the person, baselineaccelerometer data of the person, or baseline self-reported mood data ofthe person, wherein the baseline-renal-Doppler data measures a stressresponse of the sympathetic nervous system, and wherein the stress modelcorrelates the baseline renal-Doppler data and the baselineglucocorticoid data of the person with the baseline heart-rate data ofthe person, the baseline blood-pressure data of the person, the baselinepulse-oximetry data of the person, the baseline accelerometer data ofthe person, or the baseline self-reported mood data of the person; meansfor analyzing the first data set and second data set with respect toeach other and with respect to the stress model; means for determining acurrent stress factor for the stressor with respect to the person basedon the analysis of the first data set and second data set with respectto each other and with respect to the stress model; and means fortransmitting a warning to a designated computing system of the personreferencing the current stress factor if the current stress factordeviates from a set of control parameter.
 47. The system of claim 46,wherein the environmental sensor is selected from a fourth groupconsisting of a barometer, a weather sensor, a pollen counter, alocation sensor, a seismometer, an altimeter, a hydrometer, a decibelmeter, a light meter, a thermometer, a wind sensor, and a trafficsensor.
 48. The system of claim 46, wherein the environmental sensor isa data feed.
 49. The system of claim 46, the means for determining thecurrent stress factor for the stressor with respect to the person basedon the analysis of the first data set and second data set with respectto each other comprises: means for determining a first stress index ofthe person based on the first data set; means for determining a secondstress index of the person based on the second data set; and means fordetermining a current stress factor for the stressor with respect to theperson based on a comparison of the first stress index and second stressindex of the person with respect to each other.
 50. The system of claim49, wherein the data from the second sensors is used to validate thestress index of the person.
 51. The system of claim 46, wherein the datafrom the second sensors is used to validate the current stress factor ofthe person.
 52. The system of claim 46, further comprising: means foraccessing a prior stress factor for the stressor of the person thatprecedes the current stress factor; means for analyzing the currentstress factor and prior stress factor for the stressor of the personwith respect to each other; and means for determining whether there is achange in the stress factor for the stressor of the person based on theanalysis of the current stress factor and prior stress factor withrespect to each other.
 53. The system of claim 46, wherein one or moreof the sensors from the first group is affixed to the person's body. 54.The system of claim 46, wherein the stress model comprises an algorithmthat comprises a plurality of variables based on two or more of theheart-rate data of the person, the blood-pressure data of the person,the pulse-oximetry data of the person, the accelerometer data of theperson, or the self-reported mood data of the person.
 55. The system ofclaim 46, wherein: at the first time the person was stressed; and at thesecond time the person was unstressed.
 56. The system of claim 46,wherein: at the first time the person was engaged in a first activity;and at the second time the person was engaged in a second activity. 57.The system of claim 46, wherein: the first group further consists of anelectrocardiograph; and the data streams further compriseelectrocardiograph data of the person from the electrocardiograph. 58.The system of claim 46, wherein: the first group further consists of anelectromyograph; and the data streams further comprise electromyographdata of the person from the electromyograph.
 59. The system of claim 46,wherein: the first group further consists of a respiration sensor; andthe data streams further comprise respiration data of the person fromthe respiration sensor.
 60. The system of claim 46, wherein: the firstgroup further consists of a galvanic-skin-response sensor; and the datastreams further comprise galvanic-skin-response data of the person fromthe galvanic-skin-response sensor.